Dust removal fan protection device

Abstract

The utility model relates to a dust removal fan protection device. Comprising a cooling circulation main water pump main loop, a high-voltage comprehensive protection device, a PLC control system, a dust removal fan, a high-voltage switch cabinet opening coil, a water pump operation detection relay, a standby pump main loop, a machine-side main and standby selection loop, a transmission relay, a delay power-off relay, a state relay and a machine-side manual and automatic selection switch. The standby pump loop of the circulating water pump provides guarantee for main water pump faults and further guarantees switching-off of the high-voltage switch cabinet, reliable switching-off of the high-voltage switch cabinet is guaranteed through the water pump operation detection relay, the delay power-off relay, the transmission relay and the state relay, timely shutdown of a fan system is achieved, and the service life of the high-voltage switch cabinet is prolonged. Therefore, major accidents such as damage of a fan bearing, a speed regulation hydraulic coupler and a main driving motor bearing bush are avoided, the reliability of equipment operation is improved, the continuity of power supply is guaranteed through a direct current screen, and reliable opening of the high-voltage switch cabinet is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial electrical automation, in particular to a dust removal fan protection device. Background Art

[0002] The main fans of the environmental dust removal system of the blast furnace are basically medium and large equipment, and are generally driven by high-voltage motors. The fan systems currently used on site have gradually exposed some operating defects in actual operation. The main manifestation is that when the low-voltage control power supply fails or the cooling water pump stops, if the high-voltage integrated protection device also fails at the same time, the high-voltage switch cabinet that controls the motor power supply cannot be opened and shut down in time, resulting in the dust removal fan continuing to operate without cooling and heat dissipation. Especially when the cooling water pump stops due to a fault, and the main motor driving the fan cannot be opened and shut down in time, it will cause serious equipment accidents such as damage to the dust removal fan, speed regulating hydraulic coupling, fan bearing, main motor bearing, etc. due to excessive temperature rise. Since the dust removal fan requires a long time to repair and restore, there will be large environmental accidents such as dust pollution in the production site. In order to avoid dust pollution, the blast furnace will inevitably stop production, which will cause significant production losses.

[0003] The startup sequence of medium and large dust removal fans and their ancillary equipment is generally: start the circulating cooling water pump → start the circulating oil pump → start the fan main motor → adjust the speed regulating hydraulic coupling to accelerate the fan rotor → adjust the damper opening; the sequence is reversed when shutting down. The current defect of the system is that when the low-voltage power supply line fails and the system is shut down due to phase loss and tripping of the power circuit of the cooling circulating water pump, and when the high-voltage integrated protection device fails to open the control at the same time, the high-voltage switch cabinet cannot be shut down in time due to the failure of opening the switch, which in turn causes equipment operation accidents. Summary of the invention

[0004] The utility model provides a dust removal fan protection device, which adds a standby pump main circuit to provide protection for the main water pump failure, and ensures the reliable opening of the high-voltage switch cabinet through the water pump operation detection relay, delay relay, transmission relay and status relay, so as to realize the timely shutdown of the fan system and avoid the occurrence of major production losses.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A dust removal fan protection device, comprising a main circuit of a cooling circulation main water pump, a high-voltage integrated protection device, a PLC control system, a dust removal fan and a high-voltage switch cabinet opening coil, wherein the main circuit of the cooling circulation main water pump is electrically connected to the PLC control system, the high-voltage integrated protection device is electrically connected to the high-voltage switch cabinet opening coil, and the high-voltage switch cabinet opening coil is connected to the dust removal fan;

[0007] It also includes a water pump operation detection relay, a standby pump main circuit, a main and standby selection circuit beside the machine, a transmission relay, a status relay and a hand-automatic selection switch beside the machine. The water pump operation detection relay includes a main water pump operation detection relay and a standby water pump operation detection relay. The main water pump operation detection relay is connected in parallel to the main water pump input end of the main circuit of the cooling cycle main water pump, and the standby water pump operation detection relay coil is connected in parallel to the standby water pump input end of the standby pump main circuit;

[0008] The water pump operation detection relay open point is connected to the transmission relay closed point, the machine-side manual automatic selection switch includes a main water pump manual automatic selection switch and a standby water pump manual automatic selection switch, the main water pump manual automatic selection switch and the standby water pump manual automatic selection switch are electrically connected to the main circuit of the cooling cycle main water pump and the main circuit of the standby pump respectively, the output ends of the main water pump manual automatic selection switch and the standby water pump manual automatic selection switch are both connected in series with the corresponding status relay closed point and the transmission relay closed point, the series circuit is connected in parallel to the high-voltage switch cabinet opening coil, the water pump operation detection relay open point is also connected to the input end of the PLC control system, and the output module of the PLC control system is connected to the status relay; the machine-side main and standby selection circuit is electrically connected to the cooling cycle main water pump main circuit and the standby pump main circuit.

[0009] Furthermore, it also includes a delayed power-off relay, which includes a main water pump power-off delay relay and a standby water pump power-off delay relay, the opening point of the main water pump operation detection relay is connected to the main water pump power-off delay relay coil, the opening point of the standby water pump operation detection relay is connected to the standby water pump power-off delay relay coil, and the opening points of the main water pump power-off delay relay and the standby water pump power-off delay relay are connected to the coil of the transmission relay.

[0010] Furthermore, the main water pump operation detection relay and the standby water pump operation detection relay are respectively provided with three relays, the three relay coils of the main water pump operation detection relay are respectively connected in parallel to the three-phase input end of the main water pump, the three relay coils of the standby water pump operation detection relay are respectively connected in parallel to the three-phase input end of the standby water pump, the three relay opening points of the main water pump operation detection relay are connected in series and connected to the main water pump power-off delay relay coil, and the three relay opening points of the standby water pump operation monitoring relay are connected in series and connected to the standby water pump power-off delay relay coil.

[0011] Furthermore, the machine-side main-standby selection circuit includes a machine-side main-standby selection switch, a main pump relay and a standby water pump relay. One contact of the machine-side main-standby selection switch is connected to the main pump relay coil, and the other contact is connected to the standby water pump relay coil. The main pump relay opening point and the standby water pump relay opening point are connected to the input end of the PLC control system.

[0012] Furthermore, it also includes a DC panel, which is connected to the opening coil of the high-voltage switch cabinet.

[0013] Furthermore, it also includes a start button, a stop button and a thermal relay. The automatic manual selection switch beside the machine is connected in series with the start button, the stop button and the thermal relay and is self-lockingly connected to the main water pump.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1) Provide protection for the failure of the main water pump through the main circuit of the standby pump, and also provide further protection for the opening of the high-voltage switchgear;

[0016] 2) The reliable opening of the high-voltage switch cabinet is ensured through the water pump operation detection relay, delay relay, transmission relay, and status relay, so that the fan system can be shut down in time, thereby avoiding major accidents such as damage to the fan bearings, speed regulating hydraulic coupling, and main drive motor, and improving the reliability of equipment operation;

[0017] 3) The DC panel provides continuous power supply to the high-voltage switchgear operation control circuit in normal state and under AC low-voltage power supply failure state, thereby providing continuous power supply to the high-voltage switchgear opening coil. Even if the high-voltage integrated protection device fails to open the switch control, it can reliably drive the opening coil to operate, ensuring reliable opening of the high-voltage switchgear. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the main circuit wiring of the cooling cycle main water pump of the utility model.

[0019] Figure 2 This is a schematic diagram of the main circuit wiring of the standby pump described in the utility model.

[0020] Figure 3 It is a wiring diagram of a control circuit for manual and automatic selection of the main water pump described in the utility model.

[0021] Figure 4 It is a wiring diagram of a control circuit for automatic selection of a standby water pump according to the utility model.

[0022] Figure 5 It is a wiring diagram of the main water pump operation detection relay and the delay relay described in the utility model.

[0023] Figure 6 It is a wiring diagram of the standby water pump operation detection relay and the time delay relay described in the utility model.

[0024] Figure 7 It is a wiring diagram of the opening coil of the high-voltage switch cabinet described in the utility model.

[0025] Figure 8This is a wiring diagram of the PLC control system described in the utility model. DETAILED DESCRIPTION

[0026] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings:

[0027] The utility model discloses a dust removal fan protection device, comprising a main circuit of a cooling circulation main water pump, a high-voltage integrated protection device, a PLC control system, a dust removal fan, a high-voltage switch cabinet trip coil, a water pump operation detection relay, a standby pump main circuit, a machine-side main-standby selection circuit, a transmission relay, a status relay, a time-delay power-off relay, a machine-side manual automatic selection switch and a DC panel, wherein the DC panel is connected to the high-voltage switch cabinet trip coil, the main circuit of the cooling circulation main water pump is electrically connected to the PLC control system, the high-voltage integrated protection device is electrically connected to the high-voltage switch cabinet trip coil, the high-voltage switch cabinet trip coil is connected to the dust removal fan, and the water pump operation detection relay comprises a main water pump operation detection relay and a standby water pump operation detection relay.

[0028] See Figure 1-2 The main water pump operation detection relay is provided with three relays KD11, KD12, and KD13. The coils of the main water pump operation detection relays KD11, KD12, and KD13 are connected in parallel to the three-phase input end of the main water pump of the main circuit of the cooling cycle main water pump. The standby water pump operation detection relay is provided with three relays KD21, KD22, and KD23. The coils of the standby water pump operation detection relays KD21, KD22, and KD23 are connected in parallel to the standby water pump input end of the standby pump main circuit.

[0029] See Figure 3 The control circuit of the main water pump automatic manual selection is also provided with a start button, a stop button and a thermal relay. The main and standby selection circuit beside the machine is connected to the relay KA1 and KA2 coils respectively through the two outputs of the selection switch SP3. One path of the main water pump automatic manual selection switch SP1 is connected to the parallel circuit of the start button SB1 and the main water pump self-locking relay KM1, and forms a series circuit with the stop button SB2. The other path of the main water pump automatic manual selection switch SP1 is connected to the open point of the relay KX17 at the output end of the PLC control system to form a series circuit. The two series circuits are connected in parallel and connected to the thermal relay FR1 at the input end of the main water pump.

[0030] See Figure 4The standby water pump manual automatic selection switch SP2 is connected to the parallel circuit of the start button SB3 and the main water pump self-locking relay KM1 on one path, and forms a series circuit with the stop button SB4. The main water pump manual automatic selection switch SP1 is connected to the open point of the relay KX19 at the output end of the PLC control system on the other path to form a series circuit. The two series circuits are connected in parallel to the thermal relay FR2 at the input end of the standby water pump.

[0031] See Figure 5-6 The delayed power-off relay includes a main water pump power-off delay relay KT1 and a standby water pump power-off delay relay KT2. The opening points of the main water pump operation detection relays KD11, KD12, and KD13 are connected in series and connected to the coil of the main water pump power-off delay relay KT1, and the opening point of the main water pump power-off delay relay KT1 is connected to the coil of the transmission relay KA011; the opening points of the standby water pump operation detection relays KD21, KD22, and KD23 are connected in series and connected to the coil of the standby water pump power-off delay relay KT2, and the opening point of the standby water pump power-off delay relay KT2 is connected to the transmission relay KA021.

[0032] See Figure 7 The machine-side automatic manual selection switch includes a main water pump automatic manual selection switch SP1 and a standby water pump automatic manual selection switch SP2. The main water pump automatic manual selection switch SP1 is connected in series with the state relay KK21 closed point and the transmission relay KA011 closed point. The standby water pump automatic manual selection switch SP2 is connected in series with the state relay closed point KK23 closed point and the transmission relay KA021 closed point. The two series circuits are then connected in parallel to the high-voltage switch cabinet opening coil TQ.

[0033] See Figure 8 The opening points of the main water pump operation detection relays KD11, KD12, and KD13 and the opening points of the standby water pump operation detection relays KD21, KD22, and KD23 are connected to the input end of the switch quantity input module of the PLC control system, and the output terminal of the PLC control system is connected to the coils of the status relays KK21 and KK23; the opening points of the relays KA1 and KA2 that are energized after the main and standby pumps of the machine-side main and standby selection circuit are also connected to the input end of the switch quantity input module of the PLC control system.

[0034] Working principle: Under normal circumstances, the cooling circulation main water pump and the standby pump are in remote automatic control state, and the main / standby state can be determined by the main / standby selection switch. When the cooling circulation main water pump starts and operates normally, the relays KD11, KD12, and KD13 connected in parallel in the main water pump power circuit monitor the real-time operation status of the water pump. When the circulating water pump power circuit trips or fails in phase failure, this group of relays first controls the switch from the main water pump to the standby water pump. If the standby water pump fails to start, another group of detection relays KD21, KD22, and KD23 connected in parallel to the standby pump will control another power-off delay relay KT2 to operate, and the power-off delay relay KT1 or KT2 will then control the transmission relays KA011 and KA021 to directly send a trip command to the high-voltage switch cabinet trip coil TQ.

[0035] The opening command signal issued by the transmission relays KA011 and KA021 is taken from the normally closed point of the corresponding relay. During normal operation, the corresponding relay is controlled by the moving-breaking contact of the corresponding power-off delay relay and is in the energized state. When the power-off delay relay is reset due to delayed action, or when a power outage occurs in the low-voltage power supply system, the corresponding intermediate transmission relay is reset due to power failure, and its normally closed point is closed, and an opening command is directly issued to the opening coil of the high-voltage switch cabinet.

[0036] The main / standby selection switch beside the cooling circulation water pump, the water pump operating status and other signals are supplied to the PLC control system for combined logic judgment. When the cooling circulation main water pump is started and operates normally, the status control relay controlled by the PLC control system output is energized, indicating that the cooling system has entered the ready state, and its normally closed point is disconnected, shielding the function of the device.

[0037] The opening command signal issued by the transmission relay is connected in series with the remote automatic contacts of the manual / remote automatic selection switch beside the machine and the normally closed contacts of the status control relay controlled by the PLC, and then directly connected to the opening coil control circuit of the high-voltage switchgear. Even if the opening control of the high-voltage integrated protection device fails, because there is a DC panel, that is, the DC power supply with battery backup power supply provides the high-voltage switchgear operation control circuit with normal and continuous power supply under the AC low-voltage power supply failure state, thereby providing continuous power supply for the opening coil of the high-voltage switchgear. Even if a power outage occurs in the low-voltage power supply system, the opening coil can be reliably driven to operate, ensuring that the high-voltage switchgear is reliably opened and the fan system is shut down in time.

[0038] The machine-side manual / remote-automatic selection switch is used for machine-side operation control during equipment maintenance and debugging, and the function of the device is shielded after machine-side control is selected. The main water pump and the standby water pump are respectively selected into the manual-automatic idle state through the main water pump manual-automatic selection switch SP1 and the standby water pump manual-automatic selection switch SP2, and the manual-automatic state between the two pumps is not affected by each other.

[0039] Connect another set of normally open contacts of the relay used to detect the operating status of the cooling circulating water pump to the switch input module of the PLC control system. While monitoring the operating status of the circulating water pump in real time, use the signal to control the main / standby operation switching of the circulating water pump through the PLC, and appropriately adjust the action time of the power-off delay relay to ensure that the high-voltage cabinet remains in the closed state when the circulating water pump is switched between the main / standby operation.

[0040] The above embodiments are implemented based on the technical solution of the utility model, and detailed implementation methods and specific operation processes are given, but the protection scope of the utility model is not limited to the above embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims

1. A dust removal fan protection device, comprising a main circuit of a cooling cycle main water pump, a high-voltage integrated protection device, a PLC control system, a dust removal fan and a high-voltage switch cabinet opening coil, wherein the main circuit of the cooling cycle main water pump is electrically connected to the PLC control system, the high-voltage integrated protection device is electrically connected to the high-voltage switch cabinet opening coil, and the high-voltage switch cabinet opening coil is connected to the dust removal fan; It is characterized in that It also includes a water pump operation detection relay, a standby pump main circuit, a main and standby selection circuit beside the machine, a transmission relay, a status relay and a hand-automatic selection switch beside the machine. The water pump operation detection relay includes a main water pump operation detection relay and a standby water pump operation detection relay. The main water pump operation detection relay is connected in parallel to the main water pump input end of the main circuit of the cooling cycle main water pump, and the standby water pump operation detection relay coil is connected in parallel to the standby water pump input end of the standby pump main circuit; The water pump operation detection relay open point is connected to the transmission relay closed point, the machine-side manual automatic selection switch includes a main water pump manual automatic selection switch and a standby water pump manual automatic selection switch, the main water pump manual automatic selection switch and the standby water pump manual automatic selection switch are electrically connected to the main circuit of the cooling cycle main water pump and the main circuit of the standby pump respectively, the output ends of the main water pump manual automatic selection switch and the standby water pump manual automatic selection switch are both connected in series with the corresponding status relay closed point and the transmission relay closed point, the series circuit is connected in parallel to the high-voltage switch cabinet opening coil, the water pump operation detection relay open point is also connected to the input end of the PLC control system, and the output module of the PLC control system is connected to the status relay; the machine-side main and standby selection circuit is electrically connected to the cooling cycle main water pump main circuit and the standby pump main circuit.

2. A dust removal fan protection device according to claim 1, characterized in that: It also includes a delayed power-off relay, which includes a main water pump power-off delay relay and a standby water pump power-off delay relay. The opening point of the main water pump operation detection relay is connected to the main water pump power-off delay relay coil, and the opening point of the standby water pump operation detection relay is connected to the standby water pump power-off delay relay coil. The opening points of the main water pump power-off delay relay and the standby water pump power-off delay relay are connected to the coil of the transmission relay.

3. A dust removal fan protection device according to claim 2, characterized in that: The main water pump operation detection relay and the standby water pump operation detection relay are respectively provided with three relays. The three relay coils of the main water pump operation detection relay are respectively connected in parallel to the three-phase input end of the main water pump, and the three relay coils of the standby water pump operation detection relay are respectively connected in parallel to the three-phase input end of the standby water pump. The three relay opening points of the main water pump operation detection relay are connected in series and connected to the main water pump power-off delay relay coil, and the three relay opening points of the standby water pump operation monitoring relay are connected in series and connected to the standby water pump power-off delay relay coil.

4. A dust removal fan protection device according to claim 1, characterized in that: The machine-side main-standby selection circuit includes a machine-side main-standby selection switch, a main pump relay and a standby water pump relay. One contact of the machine-side main-standby selection switch is connected to the main pump relay coil, and the other contact is connected to the standby water pump relay coil. The main pump relay opening point and the standby water pump relay opening point are connected to the input end of the PLC control system.

5. A dust removal fan protection device according to claim 1, characterized in that: It also includes a DC panel connected to the opening coil of the high-voltage switch cabinet.

6. A dust removal fan protection device according to claim 1, characterized in that: It also includes a start button, a stop button and a thermal relay. The machine-side manual automatic selection switch is connected in series with the start button, the stop button and the thermal relay and is self-lockingly connected to the main water pump.

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