CN201443779U

CN201443779U - Automatic energy-saving control system for boiler

Info

Publication number: CN201443779U
Application number: CN2009200008578U
Authority: CN
Inventors: 石建兴
Original assignee: Baoding Ruwei Energy Technology Co Ltd
Current assignee: Baoding Ruwei Energy Technology Co Ltd
Priority date: 2009-01-13
Filing date: 2009-01-13
Publication date: 2010-04-28
Anticipated expiration: 2019-01-13

Abstract

The utility model relates to an automatic energy-saving control system for a boiler. The starting of four larger motors, i.e. an induced draft fan, an air blower, a fire grate and a water pump, in the boil equipment is controlled by adopting corresponding-capacity frequency converters capable of controlling and changing the rotating speed of the motors. A pressure gauge at a steam outlet of the boiler is replaced with a pressure gauge with a pressure detection sensor, and meanwhile, the original water-level gauge of the boiler is changed into a water-level detection sensor device; and a programmable controller is additionally mounted in a control cabinet. A pressure given value and a water-level given value are written into the programmable controller in advance according to user's requirements, signals detected by the pressure sensor and the water-level sensor are fed back to the programmable controller for operation and comparison, and then frequency signals are output, therefore, the rotating speed of each of the motors is reasonably controlled, the motors, i.e. the induced draft fan, the air blower, the fire grate and the water pump, are synchronously adjusted, and the purposes of outputting the constant air pressure value and saving the energy sources are achieved.

Description

Boiler automation energy-saving control system

Technical field: the invention belongs to industrial automation control field.

Background technology: Industrial Boiler is widely used in various fields such as factory power, building and heating, but owing to many-sided reasons such as design, supporting and operations, problems such as the industrial boilers in China ubiquity thermal efficiency is low, energy resource consumption is excessive, seriously polluted, the low 15%-20% of the external advanced level of average operating efficiency, the energy-saving potential of implication is very huge.At present, domestic general medium-sized and small enterprises employed 2-20 ton heating boiler, the main boiler that produces saturated vapor that adopts.Air inducing, air blast, fire grate, add hydroelectric machine be adopt traditional directly or the reduced-voltage starting mode, power frequency operation.The output pressure of boiler is observed air gauge by the fireman and is operated.

According to the interrelated data introduction, adopt the rate of load condensate of traditional heating boiler generally not high, ubiquity " low load with strong power " phenomenon.In addition, because boiler output pressure fluctuation range big (0.5-1.0MP), generally speaking, employing boiler output hyperbar, actual hypobaric situation, promptly so-called " high fever, low using " phenomenon used.

Also there is following disadvantage with conventional boiler:

(1) waste is big, pollution is big

The temperature and pressure of saturated vapor is relevant, and the big more vapor (steam) temperature of pressure is just high more.And scattering and disappearing of heat is also relevant with temperature, and temperature high heat is is more scattered and disappeared fast more.Unnecessary raising boiler output pressure has also just improved the temperature of saturated steam in drum, the transmission pipeline, has accelerated radiating rate, has caused unnecessary heat to scatter and disappear.

Boiler provides hyperbar, and technical process needs is low pressure (as cylinder about 0.3MP), thereby technical process can not obtain more heat.The equipment of that is to say needs the pressure of 0.3MP, and the most energy-conservation boiler output pressure also should be 0.3MP (considering that duct pressure loss can suitably improve), and this just meets the basic principle with the best motive force of energy.

Although modern boiler design is comparatively reasonable, but its heating flue can not be oversize, drum, air-introduced machine high-speed cruising under power frequency, the coal-fired high-temperature flue gas time of staying in boiler that produces is shorter, can not carry out heat exchange fully with the working medium in the boiler and just be discharged from, more heat energy has scattered and disappeared.The delivery temperature height causes than heavily contaminated environment simultaneously.

(2) potential safety hazard is big

The air pressure that equipment uses owing to be to obtain with air throttle, will be opened big choke valve, to obtain suitable pressure when lower boiler output pressure.If after the boiler output pressure raise, the untimely air throttle aperture that reduces will cause gas utilization unit to bear higher pressure, causes security incident.This situation appears, when often occurring in workman's fatigue, energy and not concentrating.The periodic air throttle of regulating needs to arrange to see the vapour worker that the manpower wasting phenomenon is arranged.It is also totally unfavorable to production safety that the while transmission pipeline bears higher pressure, and the output of higher air pressure, also high to the pipeline requirement of withstand voltage, the cost of will increasing input.

Traditional boiler furnace negative pressure control mode is to detect the negative pressure of burner hearth during with constant-speed operation by primary instrument when motor, compare with the negative pressure set-point again, after the PI computing, by electronic or pneumatic actuator control blower fan baffle openings degree, promptly change windage adjusting air inducing amount and reach the adjustment effect of combustion.

Summary of the invention: in order to overcome the deficiency of existing boiler control system, the utility model provides a kind of EMB-3000 boiler automation energy-saving control system, running by the boiler combustion automatic energy saving control system after the utility model improvement is: adopt programmable controller (PLC) and frequency converter to control automatically and finish, control the output frequency of frequency converter by system's initial set value and real-time value of feedback, rationally control the rotating speed of motor, thereby on the basis of stablizing the boiler output pressure, reduce output pressure, reach energy-conservation, purpose efficiently.

This system establishes seven motor altogether, controls six running parts (wherein water pump is standby) of boiler respectively, and the function of six motors is as follows respectively: the M1 slagging-off, the M2 fire grate-, M3 air-introduced machine, M4 air blast, the M5 water pump, M6 reserve pump, the upper and lower coal of M7, M2 wherein, M3, M4, M5 use four corresponding frequency converter start-up control respectively, all the other are the power frequency start-up control, and M7 is forward and backward control.

Operation principle: a kind of boiler automation energy-saving control system, it is characterized in that: at the programmable controller input port, be mounted on the pressure sensor on the boiler, the feedback signal line of level sensor, and the touch-screen of connection industrial computer, the programmable controller output port, the control terminal RS485 COM1 that connects four frequency converters also connects slagging-off M1, the binding post and the warning indicating section of coal M7 two motors up and down simultaneously; Through the programmable controller centralized Control, all aggregation of data computings of feedback signal, comparison with pressure sensor, level sensor are converted to data signal, and output order is to frequency converter.

Determine pressure difference signal by pressure given value and pressure sensor feedback signal, after the PLC computing, provide frequency signal to frequency converter FU1-FU3, by frequency converter drive respectively that M2-M4 control is drawn, air blast size and M2 control fire grate speed, and then to reach pressure set points be zero purpose with the pressure feedback difference.

Determine the water-head signal by water level set-point and level sensor signal, after the PLC computing, provide frequency signal, drive water on the M5 control water pump, and then reaching the water level settings value, to feed back difference with water level be the purpose of definite value by frequency converter to frequency converter FU4.

Through appropriate design again to the boiler electric control system, when coal enters fire grate, pressure sensor and level sensor deliver to the signal that monitors in the Programmable Logic Controller and set/compare/show, be converted to data signal, calculate, its result commands the energetic start up device that fire grate, air blast, air inducing, moisturizing, slagging-off motor are carried out scientific and reasonable control, thereby better meets production requirement.

Description of drawings: Fig. 1 is the utility model boiler automation energy-saving control system product design figure, appearance and size: 1800 (height) X600 (wide) X600 (deeply), mark 1 is the air pressure alarm indicator lamp, mark 2 is emergency stop push buttons, and mark 3 is the water-level alarm indicator lamp, and mark 4 is for stopping alarm button, mark 5 is that indicator lamp is opened in slagging-off, mark 6 is that coal bunker is opened indicator lamp, and mark 7 is that slagging-off starts, shutdown switch, and mark 8 is that coal bunker starts, shutdown switch.

Fig. 2 is the utility model boiler automation energy-saving control system switch board panel figure.

Fig. 3 is the utility model boiler automation energy-saving control system logic diagram.

Fig. 4 is the utility model boiler automation energy-saving control system elementary diagram: primary connection scheme, secondary connection principle.

The specific embodiment:

Enable old-fashioned electric control system with one week of boiler operatiopn (168 hours), record power consumption and quantity of steam and coal consumption, after enable the control of EMB3000 system with same one week of boiler operatiopn (168 hours), record power consumption and should be lower than 5%.Quantity of steam error during two kinds of standard controls should be in positive and negative 1% scope.

Its computing formula is as follows: electric weight calculates:

The consumption coal calculates:

In the formula: the old-fashioned electrical control charge value of W W ' EMB3000 controls charge value; The old-fashioned electrical control coal consumption of Q Q ' EMB3000 controls coal consumption

Claims

1. a boiler automation energy-saving control system is characterized in that: at the programmable controller input port, be mounted on the pressure sensor on the boiler, the feedback signal line of level sensor, and connect the touch-screen of industrial computer; The programmable controller output port connects the control terminal RS485 COM1 of four frequency converters, also connects slagging-off M1, the binding post and the warning indicating section of coal M7 two motors up and down simultaneously; Through the programmable controller centralized Control, all aggregation of data computings of feedback signal, comparison with pressure sensor, level sensor are converted to data signal, and output order is to frequency converter.