阅读说明：本技术 一种刮板捞渣机断链保护系统 (Chain breakage protection system of scraper slag conveyor ) 是由 皋德华 姜旭舟 潘时勇 郭剑锋 于 2019-09-18 设计创作，主要内容包括：本发明提供一种刮板捞渣机断链保护系统,断裂保护系统包括DCS控制柜、接近开关SQ3和接近开关SQ4,接近开关SQ3与接近开关SQ1并联组成前检测组件,接近开关SQ4与接近开关SQ2并联组成后检测组件,前检测组件和后检测组件分别连接至DCS控制柜的开关量输入DI1通道和开关量输入DI2通道,DCS控制柜内分别设有报警逻辑单元和保护逻辑单元,开关量输入DI1通道和开关量输入DI2通道分别连接至报警逻辑单元和保护逻辑单元的输入端,报警逻辑单元的输出端连接至刮板捞渣机的报警终端；保护逻辑单元连接至刮板捞渣机的报警终端的启停终端,避免因为接近开关松动、中间、时间继电器损坏等故障造成的断链保护误判。(The invention provides a chain breakage protection system of a scraper slag conveyor, which comprises a DCS (distributed control system) control cabinet, a proximity switch SQ3 and a proximity switch SQ4, wherein the proximity switch SQ3 and the proximity switch SQ1 are connected in parallel to form a front detection assembly, the proximity switch SQ4 and the proximity switch SQ2 are connected in parallel to form a rear detection assembly, the front detection assembly and the rear detection assembly are respectively connected to a switching value input DI1 channel and a switching value input DI2 channel of the DCS control cabinet, an alarm logic unit and a protection logic unit are respectively arranged in the DCS control cabinet, the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input ends of the alarm logic unit and the protection logic unit, and the output end of the alarm logic unit is connected to an alarm terminal of the; the protection logic unit is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor, so that the misjudgment of broken chain protection caused by the faults of loosening of a proximity switch, damage of a middle relay, damage of a time relay and the like is avoided.)

1. A chain breakage protection system of a scraper slag conveyor comprises a chain, and a front chain rotating shaft and a rear chain rotating shaft which are used for tensioning the chain, wherein one side of each of the front chain rotating shaft and the rear chain rotating shaft is respectively and correspondingly provided with a proximity switch SQ1 and a proximity switch SQ2, and the chain breakage protection system is characterized by comprising a DCS control cabinet, a proximity switch SQ3 and a proximity switch SQ4, the proximity switch SQ3 and the proximity switch SQ1 are connected in parallel to form a front detection assembly, the proximity switch SQ4 and the proximity switch SQ2 are connected in parallel to form a rear detection assembly, the front detection assembly and the rear detection assembly are respectively connected to a switching value input DI1 channel and a switching value input DI2 channel of the DCS control cabinet, an alarm logic unit and a protection logic unit are respectively arranged in the DCS control cabinet, and the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input ends of the alarm logic unit and the, the output end of the alarm logic unit is connected to an alarm terminal of the scraper slag conveyor; and the protection logic unit is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor.

2. The scraper slag conveyor chain-breaking protection system as claimed in claim 1, wherein the alarm logic unit comprises a nor gate U1 and a time delay T1, the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input end of the nor gate U1, the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input end of the nor gate U1 through a nor gate, the output end of the nor gate U1 is connected to the time delay T1, and the time delay T1 is connected to the alarm terminal of the scraper slag conveyor.

3. The scraper slag conveyor chain breakage protection system of claim 2, wherein the time delay T1 is set to 1 min.

4. The scraper slag conveyor chain breakage protection system according to claim 1, wherein the protection logic unit comprises a delayer T2, a delayer T3, a delayer T4, a delayer T5, a NOR gate U2, an AND gate C1, an AND gate C2, an AND gate C3 and an AND gate C4, the switching quantity input DI1 channel and the switching quantity input DI1 channel are respectively connected to the delayer T2 and the delayer T4, the switching quantity input DI1 channel and the switching quantity input DI1 channel are respectively connected to the delayer T3 and the delayer T5 through NOT gates, the delayer T2 is respectively connected to the AND gate C1 and the AND gate C4, the delayer T3 is respectively connected to the AND gate C2 and the AND gate C3, the delayer T3 is respectively connected to the delayer T1 and the AND gate C3, the delayer T4 and the delayer T4C 2, the AND gate C1, the AND gate C2, the AND gate C3 and the AND gate C4 are respectively connected to the input end of the NOR gate U2, and the output end of the NOR gate U2 is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor.

5. The scraper dragveyer chain breakage protection system of claim 4, wherein the delayer T2, the delayer T3, the delayer T4 and the delayer T5 are all set to 2 min.

6. The scraper dragger chain-breaking protection system of claim 1 wherein the operating voltage of the switching value input DI1 channel and the switching value input DI2 channel is DC48V which powers the proximity switch SQ1, the proximity switch SQ2, the proximity switch SQ3 and the proximity switch SQ 4.

Technical Field

The invention belongs to the technical field of scraper slag conveyors, and particularly relates to a chain breakage protection system of a scraper slag conveyor.

Background

The slag conveyor is an important auxiliary equipment of a thermal power plant, and whether the slag conveyor runs stably or not directly influences the safety of a unit. The protection of the slag conveyor is optimized, and the reliability of the slag conveyor can be improved. The chain breakage protection is an important protection for the slag conveyor, an inductance type proximity switch (hereinafter referred to as a proximity switch) arranged on a chain rotating shaft is used for detecting the rotation period of a concave position and a convex position of a mechanical part, if a time relay cannot detect an on signal and an off signal within preset 1min, the mechanical shaft is judged not to rotate, an oil pump motor is automatically stopped, and chain breakage protection action is given an alarm, so that the damage degree of equipment such as continuous rotation, chain swallowing, chain clamping and the like after chain breakage is avoided. The protection circuit is realized by a SA2 broken chain detection switching switch, KA20, KA21 intermediate relays, SQ1 and SQ2 proximity switches and a KT 1-KT 4 time relay through hard wiring. The chain breakage protection control principle of the slag conveyor is shown in figure 1;

however, in the actual use process, the chain breaking protection of the dragveyer frequently trips and gives an alarm, and hard faults, such as loosening of a proximity switch, damage of a middle relay, damage of a time relay and the like, are found through the statistical analysis of the trip fault link, so that a chain breaking protection system of the scraper dragveyer is needed.

Disclosure of Invention

The invention aims to provide a chain breakage protection system of a scraper slag conveyor, which aims to solve the problem that the chain breakage protection of the scraper slag conveyor is often misjudged due to the fact that the existing scraper slag conveyor is prone to failure in the using process of a proximity switch, an intermediate relay, a time relay and the like.

The invention provides the following technical scheme:

a chain breakage protection system of a scraper slag conveyor comprises a chain, and a front chain rotating shaft and a rear chain rotating shaft which are used for tensioning the chain, wherein one side of each of the front chain rotating shaft and the rear chain rotating shaft is respectively and correspondingly provided with a proximity switch SQ1 and a proximity switch SQ2, the breakage protection system comprises a DCS control cabinet, a proximity switch SQ3 and a proximity switch SQ4, the proximity switch SQ3 and the proximity switch SQ1 are connected in parallel to form a front detection assembly, the proximity switch SQ4 and the proximity switch SQ2 are connected in parallel to form a rear detection assembly, the front detection assembly and the rear detection assembly are respectively connected to a switching value input DI1 channel and a switching value input DI2 channel of the DCS control cabinet, an alarm logic unit and a protection logic unit are respectively arranged in the DCS control cabinet, and the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input ends of the alarm logic unit and the protection, the output end of the alarm logic unit is connected to an alarm terminal of the scraper slag conveyor; and the protection logic unit is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor.

Further, the alarm logic unit comprises a nor gate U1 and a time delay T1, the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input end of the nor gate U1, the switching value input DI1 channel and the switching value input DI2 channel are respectively connected to the input end of the nor gate U1 through a nor gate, the output end of the nor gate U1 is connected to the time delay T1, and the time delay T1 is connected to the alarm terminal of the scraper slag conveyor.

Further, the delay timer T1 is set to 1 min.

Further, the protection logic unit includes a delayer T, a nor gate U, an and gate C, and a and gate C, the switching value input DI channel and the switching value input DI channel are respectively connected to the delayer T and the delayer T through a not gate, the delayer T is respectively connected to the and gate C and the and gate C, the and gate C and the nor gate C are respectively connected to an input end of the nor gate U, the output end of the NOR gate U2 is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor.

Further, the delayer T2, the delayer T3, the delayer T4 and the delayer T5 are all set to 2 min.

Further, the operating voltage of the switching value input DI1 channel and the switching value input DI2 channel is DC48V, which supplies power to the proximity switch SQ1, the proximity switch SQ2, the proximity switch SQ3, and the proximity switch SQ 4.

The invention has the beneficial effects that:

the invention relates to a chain breakage protection system of a scraper slag conveyor, which is characterized in that a proximity switch SQ3 and a proximity switch SQ4 are respectively additionally arranged on one side of an original proximity switch SQ1 and one side of an original proximity switch SQ2 to be connected in parallel to detect on and off signals of the proximity switch; after the proximity switches are added, when the on and off signals of 1 proximity switch on any side cannot be detected due to faults caused by large shaking, friction and the like, the other 1 proximity switches connected in parallel can synchronously make up the detection so as to reduce the probability of misoperation caused by the fact that the on and off signals of the chain rotating shaft cannot be detected by the proximity switches; the proximity switches SQ1, SQ2, SQ4 and SQ4 are respectively connected to the DCS control cabinet, so that an intermediate link is avoided, on and off signals of the proximity switches are directly used as switching value input to be provided to the DCS for displacement judgment, and chain breakage protection misjudgment caused by faults such as proximity switch looseness, intermediate faults, time relay damage and the like is avoided.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a prior art protective circuit diagram of a drag-flight slag conveyor;

FIG. 2 is a schematic circuit diagram of the chain-breaking protection system of the present invention;

FIG. 3 is a schematic diagram of the DCS control cabinet circuit of the present invention.

Detailed Description

As shown in fig. 2, a chain breakage protection system for a scraper slag conveyor comprises a chain, and a front chain rotating shaft and a rear chain rotating shaft for tensioning the chain, wherein one side of each of the front chain rotating shaft and the rear chain rotating shaft is respectively and correspondingly provided with a proximity switch SQ1 and a proximity switch SQ2, the breakage protection system comprises a DCS control cabinet, a proximity switch SQ3 and a proximity switch SQ4, the proximity switch SQ3 and the proximity switch SQ1 are connected in parallel to form a front detection assembly, the proximity switch SQ4 and the proximity switch SQ2 are connected in parallel to form a rear detection assembly, the front detection assembly and the rear detection assembly are respectively connected to a switching value input DI1 channel and a switching value input DI2 channel of the DCS control cabinet, the working voltages of the switching value input DI1 channel and the switching value input DI2 channel are DC48V, and the working voltages of the proximity switch SQ2, the proximity switch SQ3 and the proximity switch SQ4 supply power; an alarm logic unit and a protection logic unit are respectively arranged in the DCS control cabinet, a switching value input DI1 channel and a switching value input DI2 channel are respectively connected to the input ends of the alarm logic unit and the protection logic unit, and the output end of the alarm logic unit is connected to an alarm terminal of the scraper slag conveyor; the protection logic unit is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor.

As shown in fig. 3, the alarm logic unit includes a nor gate U1 and a time delay T1, a switching value input DI1 channel and a switching value input DI2 channel are respectively connected to an input end of a nor gate U1, a switching value input DI1 channel and a switching value input DI2 channel are respectively connected to an input end of a nor gate U1 through a nor gate, an output end of the nor gate U1 is connected to a time delay T1, the time delay T1 is connected to an alarm terminal of the scraper slag conveyor, and the time delay T1 is set to 1 min.

The protection logic unit comprises a delayer T2, a delayer T3, a delayer T4, a delayer T5, a NOR gate U2, an AND gate C1, an AND gate C2, an AND gate C3 and an AND gate C4, a switching quantity input DI1 channel and a switching quantity input DI1 channel are respectively connected to the delayer T2 and the delayer T4, a switching quantity input DI1 channel and a switching quantity input DI1 channel are respectively connected to the delayer T3 and the delayer T5 through NOT gates, the delayer T2 is respectively connected to the AND gate C1 and the AND gate C4, the delayer T3 is respectively connected to the AND gate C2 and the AND gate C3, the delayer T3 is respectively connected to the AND gate C1 and the AND gate C3, the delayer T4 is respectively connected to the AND gate C2 and the AND gate C4, the AND gate C1, the AND gate C2, the AND gate C3 and the AND gate C4 are respectively connected to the input terminal of the NOR gate U2, the output end of the NOR gate U2 is connected to a start-stop terminal of an alarm terminal of the scraper slag conveyor, and the delayer T2, the delayer T3, the delayer T4 and the delayer T5 are all set to be 2 min.

In the specific embodiment, a link of chain breakage protection hard wiring in a slag conveyor control cabinet is cancelled, and an intermediate relay, a time relay, a chain breakage protection tripping relay, a tripping indicator lamp, a throw-in switch and a cut-off switch are removed; the hard wiring and the components thereof for realizing the chain breakage protection principle are cancelled, so that the misoperation of the intermediate and time relays due to the reasons of electric service life, instant failure and the like can be avoided from the source;

an operation indicator lamp on a panel of the slag remover control cabinet is reserved; the method comprises the steps that an original proximity switch SQ1 and an original proximity switch SQ2 on a chain rotating shaft are reserved, 1 proximity switch SQ3 and an existing proximity switch SQ4 are added, and on-off signals of the proximity switches are detected in parallel; after the proximity switches are added, when the on-off signals of 1 proximity switch on any side cannot be detected due to the faults caused by large shaking, friction and the like, the other 1 proximity switches connected in parallel can synchronously make up the detection so as to reduce the probability of misoperation caused by the fact that the on-off signals of the chain rotating shaft cannot be detected by the proximity switches. .

Approach switches SQ1, SQ2, SQ3 and SQ4 of the slag conveyor are directly connected to DI1 and DI2 channels on a DI (switching value input) clamping piece in a DCS cabinet, so that an intermediate link is avoided, and on and off signals of the approach switches are directly used as switching value input to be provided for DCS to carry out displacement judgment; the interrogation operating voltage of each channel of the DI card is DC48V, which is also used as the operating power source for the proximity switch.

Performing logic configuration in the DCS: DCS can not detect the on-off signals of any side proximity switches of DI1 and DI2 within 1min, and sends alarm signals on CRT pictures; the DCS can not detect the on and off signals of the DI1 and DI2 proximity switches within 2min at the same time, directly sends a command of stopping the dragveyer and sends a fault tripping signal on a CRT picture; a chain-breaking protection switching switch is added on a CRT picture.

As can be seen from fig. 3, when the CRT screen "chain breakage protection switching switch" is turned on, the DCS logic configuration determines the displacement of 4 proximity switches on both sides, and the following results exist:

① DCS can not detect the on and off signals of any side approach switch of DI1 and DI2 within 1min, and sends alarm signal on CRT picture, on one hand, the operator sees the alarm signal to inform the overhaul to check the status of on-site approach switch in time, on the other hand, DCS does not send out the order of shutting down the dragveyer immediately, avoiding the abnormal or damaged approach switch on the abnormal side, actually the dragveyer is still in normal operation state and is misoperated.

② DCS can not detect the on and off signals of DI1 and DI2 proximity switches within 2min, directly sends out the command of the dragveyer to stop running, and sends out the fault trip signal on CRT picture.

Wherein, DI1, DI2 are in 1-0 overturning process continuously in the chain rotating shaft rotating process. When the proximity switch detects the convex tooth of the gear, the corresponding DI1 or DI2 is 1, and the passing NOT gate is 0; when the proximity switch detects the groove of the gear, the corresponding DI1 or DI2 is 0, the not gate is 1, and the setting value is according to: the actual measurement of the running speed of the slag conveyor is 1m/min, the total length of a chain of the slag conveyor is 112.14 m, and if the chain only slides for about 2m when the chain is broken for 2min, the damage degree of expanding equipment such as swallow chain, chain clamping and the like is not enough.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.