Temperature and combustible concentration automatic control fan circuit and forward and reverse rotation control method thereof

Abstract

The invention relates to a fan circuit capable of automatically controlling temperature and combustible concentration, which is characterized in that three phases of a fan power supply are connected with a fan through a forward contactor contact and a fan thermal relay in sequence, a reverse contactor contact is connected to the forward contactor contact in parallel, and any two phases connected out of a reverse contactor are opposite to the corresponding two phases of the forward contactor; a controller power supply is divided into three paths after passing through a fan thermal relay normally-closed switch and a power supply monitor normally-closed switch, the first path is sequentially provided with a local start button, a stop button and an intermediate relay, and the local start button is connected with an intermediate relay normally-open switch in parallel; the second path is sequentially provided with an intermediate relay normally-open switch, a temperature controller normally-closed switch, a combustible gas detector normally-closed switch, a reverse rotation contactor time delay switch and a forward rotation contactor, and the third path is sequentially provided with an intermediate relay normally-open switch, a combustible gas detector normally-open switch, a forward rotation contactor time delay switch and a reverse rotation contactor; the circuit can automatically control forward and reverse rotation and exhaust, and safety control is considered.

Description

Technical Field

[0001] The invention relates to a marine fan technology, in particular to a temperature and combustible concentration automatic control fan circuit and a forward and reverse rotation control method thereof. Background Art

[0002] There are several common practices for controlling air supply and exhaust in marine explosion-proof areas: using two fans, one for air supply and the other for exhaust, which is relatively costly; using manual control of fan forward and reverse rotation, which has no basis for air supply and exhaust parameters and is not reliable; there is no time delay interlock for the forward and reverse switching of the fan, resulting in reverse inertia switching, which can easily cause damage. Summary of the invention

[0003] The present invention provides a fan circuit capable of automatically controlling forward and reverse rotation of air supply and exhaust, taking into account temperature and combustible concentration automatic control of safety control, and a forward and reverse rotation control method thereof.

[0004] The technical solution adopted by the present invention is: a temperature and flammable concentration automatic control fan circuit, including a fan circuit and a control circuit, the control circuit includes a forward contactor and, the fan power three-phase of the fan circuit is connected to the fan UVW three-phase in sequence through the forward contactor contact and the fan thermal relay, characterized in that: it also includes a reverse contactor, the reverse contactor contact is connected in parallel to the forward contactor contact, the connection of any two phases of the three phases connected by the reverse contactor is opposite to the corresponding two-phase connection of the forward contactor, and the three phases of the power supply circuit are also connected to the power supply monitor; the control circuit also includes a fan thermal relay normally closed switch, a power supply monitor normally closed switch, a local start button, a local stop button The controller power supply is connected to the control power supply in three ways after passing through the normally closed switch of the fan thermal relay and the normally closed switch of the power monitor. The local start button, the local stop button and the intermediate relay are set in sequence in the first way. The first normally open switch of the intermediate relay is connected in parallel to the local start button. The second way is set in sequence with the second normally open switch of the intermediate relay, the normally closed switch of the temperature controller, the normally closed switch of the combustible gas detector, the normally closed power-off delay switch of the reversing contactor and the forward contactor. The third way is set in sequence with the third normally open switch of the intermediate relay, the normally open switch of the combustible gas detector, the normally open power-off delay switch of the forward contactor and the reversing contactor.

[0005] Indicator lights are connected in parallel to the forward contactor and the reverse contactor.

[0006] The local start button and the local stop button are buttons that connect when pressed and pop up when released.

[0007] The local start button is connected in parallel with a remote start button, and the first path is connected in series with a remote stop button.

[0008] A method for controlling the forward and reverse rotation of a fan circuit that automatically controls temperature and flammable concentration, characterized in that: a. Fan circuit power supply monitoring: the power supply monitor monitors the voltage, phase error and phase loss of the fan power supply in real time, and controls the opening and closing of the normally closed switch of the power supply monitor; b. When the fan power supply is abnormal, press the local start button or the remote start button, the normally closed switch of the power monitor is disconnected, the first, second and third control circuits are not energized, the forward contactor and the reverse contactor are not energized, the forward contactor contacts and the reverse contactor contacts are not closed, the fan is not energized and does not work; c. When the fan power supply is normal, press the local start button or the remote start button, the intermediate relay of the first circuit is energized, and the first normally open switch of the intermediate relay is closed. At this time, release the local start button or the remote start button to lock the power supply of the first circuit; the second normally open switch of the intermediate relay of the second circuit is closed, the normally closed switch of the temperature controller and the normally closed switch of the combustible gas detector receive the signals of the temperature controller and the combustible gas detector. When there is no abnormality, the two normally closed switches remain closed, the second forward contactor is energized, the indicator light is on, the forward contactor contacts are closed, the fan power supply is connected to the fan, and the fan starts to supply air in the forward direction; at this time, the normally open switch of the combustible gas detector of the third circuit remains open, and the third circuit is de-energized; d. Under abnormal temperature conditions, when the forward temperature of the fan is detected to be too high by the temperature controller, the normally closed switch of the temperature controller is disconnected, the second circuit is disconnected, the forward contactor loses power, and the fan stops; e. Under abnormal combustible gas conditions, when the forward combustible gas detector detects that the combustible gas concentration is too high, the normally closed switch of the combustible gas detector is disconnected, the normally open switch of the combustible gas detector is closed, the second circuit is disconnected, the forward contactor loses power, the forward contactor normally open power-off delay switch is delayed and closed after the fan stops rotating forward, the third circuit is connected and energized, the reverse contactor is energized, and the fan reverses to exhaust air; f. The fan is overheated, the fan thermal relay controls the normally closed switch of the fan thermal relay to be disconnected, the control circuit is powered off, and the fan stops; g. The fan is abnormal, the power monitor controls the normal power monitor switch to be disconnected, the control circuit is powered off, and the fan stops; h. Local shutdown or remote shutdown: press the local stop button or the remote stop button, the first intermediate relay is de-energized, the first, second, and third normally open switches of the intermediate relay are opened and closed, the control circuit is de-energized, and the fan is shut down.

[0009] The beneficial effects of the present invention are: the use of a start button for control has a relatively high cost-effectiveness and reliability. The fan uses a thermal relay to participate in the control, which plays a role in overcurrent protection. The fan uses a power monitor with overvoltage, undervoltage, phase error, and phase loss protection functions. The temperature controller monitors the forward temperature and controls the fan to rotate forward for forward air supply. The combustible gas detector monitors the combustible gas concentration and controls the fan to reverse for exhaust. When both the temperature and combustible gas concentration parameters meet the standards, the combustible gas concentration signal parameter is better than the temperature control. At this time, the forward rotation is cut off and the fan is operated in reverse. There is a delay function when switching between forward and reverse rotation. The power-off delay head is used to completely stop the fan before the switching state before entering the next mode to avoid reverse inertia startup. A remote operation start button is provided to facilitate remote operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is the circuit diagram of the fan of the present invention; Figure 2 This is a control circuit diagram of the present invention.

[0011] In the figure: fan power supply 1, controller power supply 2, power supply monitor K, power supply monitor normally closed switch K-1, fan thermal relay FR, fan thermal relay normally closed switch FR-1, fan M, local start button SB1, local stop button SB2, remote start button SB3, remote stop button SB4, intermediate relay KA, intermediate relay first normally open switch KA-1, intermediate relay second normally open switch KA-2, intermediate relay third normally open switch KA-3, temperature controller normally closed switch ST, combustible gas detector normally closed switch PPM-1, combustible gas detector normally open switch PPM-2, forward contactor KM1, forward contactor contact KM1-1, forward contactor normally open power-off delay switch KM1-2, reverse contactor KM2, reverse contactor contact KM2-1, reverse contactor normally closed power-off delay switch KM2-2. DETAILED DESCRIPTION

[0012] The following is a further description with reference to the accompanying drawings.

[0013] Figure 1 , 2As shown: a temperature and combustible concentration automatic control fan circuit, including a fan power supply 1, a controller power supply 2, and the three phases of the fan power supply 1 are connected to the UVW three phases of the fan M in sequence through the forward contactor contact KM1-1 and the fan thermal relay FR, the reverse contactor contact KM2-1 is connected in parallel to the forward contactor contact KM1-1, the connection of any two phases of the three phases connected by the reverse contactor is opposite to the corresponding two phases of the forward contactor, and the fan power supply 1 is also connected to the power monitor K. The controller power supply 2 is connected to the control power supply in three ways after passing through the normally closed switch FR-1 of the fan thermal relay and the normally closed switch K-1 of the power monitor. The first way is sequentially provided with the local start button SB1, the remote stop button SB4, the local stop button SB2 and the intermediate relay KA. The local start button SB1 is connected in parallel with the first normally open switch KA-1 and the remote start button SB3 of the intermediate relay. The second way is sequentially provided with the second normally open switch KA-2 of the intermediate relay, the normally closed switch ST of the temperature controller, the normally closed switch PPM-1 of the combustible gas detector, the normally closed power-off delay switch KM2-2 of the reversing contactor and the forward contactor KM1. The forward indicator light HL1 is connected in parallel with the forward contactor KM1. The third way is sequentially provided with the third normally open switch KA-3 of the intermediate relay, the normally open switch PPM-2 of the combustible gas detector, the normally open power-off delay switch KM1-2 of the forward contactor and the reversing contactor KM2. The reversing indicator light HL2 is connected in parallel with the reversing contactor KM2.

[0014] A forward and reverse control method for a temperature and flammable concentration automatic control fan circuit: a. Fan circuit power supply monitoring: the power supply monitor K monitors the voltage, phase error and phase loss of the fan power supply in real time, and controls the opening and closing of the normally closed switch K-1 of the power supply monitor; b. When the fan power supply is abnormal, press the local start button SB1 or the remote start button SB3, the power monitor normally closed switch K-1 is disconnected, the first, second and third control circuits are not energized, the forward contactor KM1 and the reverse contactor KM2 are not energized, the forward contactor contact KM1-1 and the reverse contactor KM2-1 contacts are not closed, the fan M is not energized and does not work; c. When the fan power supply 1 is in normal state, press the local start button or the remote start button, the intermediate relay KA of the first circuit is energized, and the first normally open switch KA-1 of the intermediate relay is closed. At this time, release the local start button or the remote start button to lock the power supply of the first circuit; the second normally open switch K2-1 of the intermediate relay of the second circuit is closed, the normally closed switch ST of the temperature controller and the normally closed switch PPM-1 of the combustible gas detector receive the signals of the temperature controller and the combustible gas detector. When there is no abnormality, the two normally closed switches remain closed, the second forward contactor KM1 is energized, the indicator light is on, the forward contactor contact KM1-1 is closed, and the fan power supply 1 is connected to the fan M, and the fan M starts to supply air in the forward direction; at this time, the normally open switch PPM-2 of the combustible gas detector of the third circuit remains open, and the third circuit is de-energized; d. Under abnormal temperature conditions, when the forward temperature of the fan is detected to be too high by the temperature controller, the normally closed switch ST of the temperature controller is disconnected, the second circuit is disconnected, the forward contactor KM1 loses power, and the fan M stops; e. In the abnormal state of combustible gas, when the forward combustible gas detector detects that the combustible gas concentration is higher than the setting, the combustible gas detector normally closed switch PPM-1 is disconnected, the combustible gas detector normally open switch PPM-2 is closed, the second circuit is disconnected, the forward contactor KM1 loses power, the forward contactor normally open power-off delay switch KM1-2 is delayed to close after the forward rotation of the fan M stops, the third circuit is connected and energized, the reverse contactor KM2 is energized, and the fan M delays reverse to exhaust air; when the forward combustible gas detector detects that the combustible gas concentration is lower than the setting, the combustible gas detector normally closed switch PPM-1 is closed, the combustible gas detector normally open switch PPM-2 is disconnected, the reverse contactor KM2 loses power, the fan stops reversing, the reverse contactor normally closed power-off delay switch KM2-2 is delayed to close, and the fan reverses and supplies air after the demonstration; f. The fan is overheated, the fan thermal relay FR controls the fan thermal relay normally closed switch FR-1 to disconnect, the control circuit is powered off, and the fan stops; g. The fan is abnormal, the power monitor K controls the normal power monitor switch K-1 to be disconnected, the control circuit is powered off, and the fan stops; h. Local shutdown or remote shutdown: press the local stop button SB2 or the remote stop button SB4, the intermediate relay KA of the first circuit is de-energized, the first, second and third normally open switches of the intermediate relay are opened and closed, the control circuit is de-energized, and the fan M is shut down.

Claims

1. A temperature and flammable concentration automatic control fan circuit, including a fan circuit and a control circuit, the control circuit includes a forward contactor and, the fan power three-phase of the fan circuit is connected to the fan UVW three-phase in sequence through the forward contactor contact and the fan thermal relay, characterized in that: It also includes a reversing contactor, the reversing contactor contact is connected in parallel with the forward contactor contact, the connection of any two phases of the three phases connected by the reversing contactor is opposite to the corresponding two phases of the forward contactor, and the three phases of the power supply circuit are also connected to the power supply monitor; the control circuit also includes a fan thermal relay normally closed switch, a power monitor normally closed switch, a local start button, a local stop button, an intermediate relay and a reversing contactor, the controller power supply is connected back to the control power supply in three ways after passing through the fan thermal relay normally closed switch and the power monitor normally closed switch, the first way is sequentially provided with a local start button, a local stop button and an intermediate relay, the local start button is connected in parallel with a first normally open switch of the intermediate relay, the second way is sequentially provided with a second normally open switch of the intermediate relay, a temperature controller normally closed switch, a combustible gas detector normally closed switch, a reversing contactor normally closed power-off delay switch and a forward contactor, the third way is sequentially provided with a third normally open switch of the intermediate relay, a combustible gas detector normally open switch, a forward contactor normally open power-off delay switch and a reversing contactor.

2. A temperature and flammable concentration automatic control fan circuit according to claim 1, characterized in that: Indicator lights are connected in parallel to the forward contactor and the reverse contactor.

3. A temperature and flammable concentration automatic control fan circuit according to claim 1, characterized in that: The local start button and the local stop button are buttons that connect when pressed and pop up when released.

4. A temperature and flammable concentration automatic control fan circuit according to claim 1, characterized in that: The local start button is connected in parallel with a remote start button, and the first path is connected in series with a remote stop button.

5. A method for controlling the forward and reverse rotation of a fan circuit automatically controlled by temperature and flammable concentration according to any one of claims 1 to 4, characterized in that: a. Fan circuit power supply monitoring: the power supply monitor monitors the voltage, phase error and phase loss of the fan power supply in real time, and controls the opening and closing of the normally closed switch of the power supply monitor; b. When the fan power supply is abnormal, press the local start button or the remote start button, the normally closed switch of the power monitor is disconnected, the first, second and third control circuits are not energized, the forward contactor and the reverse contactor are not energized, the forward contactor contacts and the reverse contactor contacts are not closed, the fan is not energized and does not work; c. When the fan power supply is normal, press the local start button or the remote start button, the intermediate relay of the first circuit is energized, and the first normally open switch of the intermediate relay is closed. At this time, release the local start button or the remote start button to lock the power supply of the first circuit; the second normally open switch of the intermediate relay of the second circuit is closed, the normally closed switch of the temperature controller and the normally closed switch of the combustible gas detector receive the signals of the temperature controller and the combustible gas detector. When there is no abnormality, the two normally closed switches remain closed, the second forward contactor is energized, the indicator light is on, the forward contactor contacts are closed, the fan power supply is connected to the fan, and the fan starts to supply air in the forward direction; at this time, the normally open switch of the combustible gas detector of the third circuit remains open, and the third circuit is de-energized; d. Under abnormal temperature conditions, when the forward temperature of the fan is detected to be too high by the temperature controller, the normally closed switch of the temperature controller is disconnected, the second circuit is disconnected, the forward contactor loses power, and the fan stops; e. Under abnormal combustible gas conditions, when the forward combustible gas detector detects that the combustible gas concentration is too high, the normally closed switch of the combustible gas detector is disconnected, the normally open switch of the combustible gas detector is closed, the second circuit is disconnected, the forward contactor loses power, the forward contactor normally open power-off delay switch is delayed and closed after the fan stops rotating forward, the third circuit is connected and energized, the reverse contactor is energized, and the fan reverses to exhaust air; f. The fan is overheated, the fan thermal relay controls the normally closed switch of the fan thermal relay to be disconnected, the control circuit is powered off, and the fan stops; g. The fan is abnormal, the power monitor controls the normal power monitor switch to be disconnected, the control circuit is powered off, and the fan stops; h. Local shutdown or remote shutdown: press the local stop button or the remote stop button, the first intermediate relay is de-energized, the first, second, and third normally open switches of the intermediate relay are opened and closed, the control circuit is de-energized, and the fan is shut down.

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