CN215929627U

CN215929627U - System for preventing boiler fire extinguishing protection unwanted operation

Info

Publication number: CN215929627U
Application number: CN202122568369.0U
Authority: CN
Inventors: 秦祖斌; 王启延; 李俊; 王贵鲜; 蒋帮红
Original assignee: Guizhou Chitianhua Tongzi Chemical Co ltd
Current assignee: Guizhou Chitianhua Tongzi Chemical Co ltd
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2022-03-01
Anticipated expiration: 2031-10-25

Abstract

The utility model discloses a system for preventing boiler fire-extinguishing protection misoperation, which carries out logic judgment on flame loss of a whole hearth according to layered flame detection and hearth negative pressure detection and by combining a flame detection signal and a hearth negative pressure value, and triggers fire-extinguishing protection action of flame loss of the whole hearth. According to the utility model, the flame detection signal and the hearth negative pressure value are combined to carry out the logical judgment of the flame loss of the whole hearth, so that the judgment is more comprehensive, the reliability is good, and the accuracy and the safety are high; in addition, the delay protection operation is added, the probability of false fire extinguishing by flame loss protection of the whole furnace chamber is ensured to be zero, the boiler is ensured to operate stably, and reliable guarantee is provided for stable and high-load operation of a boiler plant.

Description

System for preventing boiler fire extinguishing protection unwanted operation

Technical Field

The utility model relates to a system for preventing boiler fire-extinguishing protection misoperation, and belongs to the technical field of boiler equipment.

Background

In order to prevent the boiler from being exploded due to the fact that fuel is continuously fed into a boiler furnace after the boiler is put out of fire, a boiler furnace safety monitoring system is required to be provided with a whole-furnace flame loss protection logic in DL/T435-2018 of boiler furnace explosion prevention regulations of power station boilers, and the boiler is stopped to operate in time to protect the boiler safety.

Full hearth flame loss (loss all flame): when the fire extinguishing signal detected by each layer of flame detector is greater than 2/4 (namely 3/4) by adopting a single burner flame detection or layer flame detection mode, the loss of the flame in the whole furnace is defined. Because the distance that the flame detector detects pulverized coal burning is comparatively fixed, lead to in the boiler to break down the burnt, break down the ash and other factors lead to the coal quality change, after the load change, flame detector can't detect flame, and the mistake sends out no fire signal. When a plurality of flame detectors cannot detect flame, the flame in the whole furnace is triggered to lose the fire extinguishing protection action, so that the boiler extinguishes fire. Boiler tripping has a very serious influence on a self-contained power plant, and can cause the whole chemical plant to stop, even cause serious environmental protection and safety accidents.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present invention provides a system for preventing malfunction of fire extinguishing protection for boilers, which can overcome the disadvantages of the prior art.

The purpose of the utility model is realized by the following technical scheme:

the utility model provides a prevent system that boiler fire suppression protection maloperation, its includes all is equipped with flame detector and negative pressure sensor on every boiler furnace, flame detector and negative pressure sensor are connected with the PLC controller electricity, and the PLC controller links to each other with the time relay circuit of control boiler gate.

The PLC is provided with a flame signal acquisition module, a negative pressure signal acquisition module, a logic judgment module and a signal output module,

the flame signal acquisition module is used for acquiring a fireless signal of each layer in the hearth;

the negative pressure signal acquisition module is used for acquiring a negative pressure value in each hearth;

the logic judgment module is used for carrying out the logic judgment of the flame loss of the whole furnace according to the fireless signal and the negative pressure value;

the signal output module is used for sending a fire extinguishing protection instruction to the time relay to trigger the fire extinguishing protection action of flame loss of the whole furnace.

The flame detector is an integrated full-wavelength dynamic flame detection device of Nanjing Wan and WHKF-2 type.

Compared with the prior art, the utility model discloses a system for preventing boiler fire-extinguishing protection misoperation, which comprises a flame detector and a negative pressure sensor which are arranged on each boiler furnace, wherein the flame detector and the negative pressure sensor are electrically connected with a PLC (programmable logic controller), and the PLC is connected with a time relay circuit for controlling a boiler gate. According to layered flame detection and hearth negative pressure detection, combined with a flame detection signal and a hearth negative pressure value, performing full-hearth flame loss logical judgment to trigger full-hearth flame loss fire extinguishing protection action, specifically, detecting the total fire detection number of each layer, and judging that fire is extinguished when a fire extinguishing signal detected by a flame detector in one layer is greater than 2/4; when all the layers are judged to be fire extinguishing, negative pressure value changes are detected in any two hearths, and the negative pressure value of at least one hearth is larger than a preset negative pressure value, so that the complete hearth flame loss is judged, and the complete hearth flame loss tripping is triggered. The utility model combines the flame detection signal and the negative pressure value of the hearth to carry out the logical judgment of flame loss of the whole hearth, can effectively prevent the fire extinguishing protection of the boiler from misoperation, ensures that the MFT cannot be triggered by the fire-free signal of the whole hearth caused by coke collapse, ash falling and other non-fire extinguishing conditions, and ensures the safety of boiler equipment by triggering the MFT to stop fuel to continuously enter the hearth when the boiler extinguishes the fire in the whole hearth really caused by burning fire. Meanwhile, the fire extinguishing of the whole furnace chamber of the boiler caused by non-combustion deterioration can be effectively prevented.

Has the advantages that:

the method optimizes the logical judgment of the flame loss of the whole furnace, so that the judgment is more comprehensive, the reliability is good, and the accuracy and the safety are high; in addition, the delay protection operation is added, the probability of false fire extinguishing by flame loss protection of the whole furnace chamber is ensured to be zero, the boiler is ensured to operate stably, and reliable guarantee is provided for stable and high-load operation of a boiler plant.

Additional advantages, objects, and features of the utility model will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the utility model. The objectives and other advantages of the utility model may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings, in which:

fig. 1 is a schematic diagram of the structure of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the preferred embodiments are illustrative of the utility model only and are not limiting upon the scope of the utility model.

As shown in figure 1, the device for preventing boiler fire-extinguishing protection misoperation comprises a flame detector 2 and a negative pressure sensor 3 which are arranged on each boiler furnace 1, wherein the flame detector 2 and the negative pressure sensor 3 are electrically connected with a PLC (programmable logic controller) 4, and the PLC 4 is electrically connected with a time relay 5 for controlling a boiler gate.

The PLC 4 is provided with a flame signal acquisition module 401, a negative pressure signal acquisition module 402, a logic judgment module 403 and a signal output module 404,

the flame signal acquisition module 401 is used for acquiring fireless signals of each layer in the hearth 1;

the negative pressure signal acquisition module 402 is used for acquiring a negative pressure value in each hearth 1;

the logic judgment module 403 is used for performing the logic judgment of the flame loss of the whole furnace according to the fireless signal and the negative pressure value;

the signal output module 404 is used for sending a fire extinguishing protection instruction to the time relay contact 5 to trigger the fire extinguishing protection action of the flame loss of the whole furnace.

The flame detector 2 is an integrated full-wavelength dynamic flame detection device of Nanjing Wan and WHKF-2 type.

The detection principle is as follows:

according to the layered flame detection and the hearth negative pressure detection, the flame detection signal and the hearth negative pressure value are combined to carry out the logical judgment of the flame loss of the whole hearth, and the fire extinguishing protection action of the flame loss of the whole hearth is triggered.

Specifically, detecting the total number of lost fire tests per floor:

when a fire extinguishing signal detected by a layer of flame detectors is greater than 2/4, the layer is judged to extinguish fire;

when all the layers are judged to be fire extinguishing, negative pressure value changes are detected in any two hearths, and the negative pressure value of at least one hearth is larger than a preset negative pressure value, so that the complete hearth flame loss is judged, and the complete hearth flame loss tripping is triggered.

The fire detection of the hearth is divided into three layers, and when 3/4 of the total fire detection amount is lost in each layer, the layer is judged to extinguish fire; when the three layers judge that the fire is extinguished, one or two negative pressure values in any two hearths are larger than a preset negative pressure value, and the fire extinguishing protection of the whole hearths is triggered.

The preset negative pressure value is-500 Pa to-550 Pa.

In order to prevent misjudgment, when the flame in the whole furnace is judged to be lost, the time-delay fire extinguishing protection is triggered.

Preferably, after the flame detection signal and the hearth negative pressure value are combined to judge that the flame of the whole hearth is lost, the tripping of the flame loss of the whole hearth is delayed for 3 seconds.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention without departing from the technical spirit of the present invention are within the scope of the present invention.

Claims

1. A system for preventing boiler fire extinguishing protection unwanted operation is characterized in that: the device comprises a flame detector (2) and a negative pressure sensor (3) which are arranged on each boiler furnace (1), wherein the flame detector (2) and the negative pressure sensor (3) are electrically connected with a PLC (programmable logic controller) (4), and the PLC (4) is connected with a time relay (5) circuit for controlling a boiler gate.

2. A system for preventing boiler fire suppression protection malfunction according to claim 1, wherein: the PLC (4) is provided with a flame signal acquisition module (401), a negative pressure signal acquisition module (402), a logic judgment module (403) and a signal output module (404),

the flame signal acquisition module (401) is used for acquiring fireless signals of each layer in the hearth (1);

the negative pressure signal acquisition module (402) is used for acquiring a negative pressure value in each hearth (1);

the logic judgment module (403) is used for performing the logic judgment of the flame loss of the whole furnace according to the fireless signal and the negative pressure value;

the signal output module (404) is used for sending a fire extinguishing protection instruction to the time relay (5) and triggering the action of fire extinguishing protection of flame loss of the whole furnace.

3. A system for preventing boiler fire suppression protection malfunction according to claim 2, wherein: the flame detector (2) is an integrated full-wavelength dynamic flame detection device of Nanjing Wan and WHKF-2 type.