CN2195736Y - Micro-computer controller for pulse burning water heating stove - Google Patents

Abstract

The utility model relates to a controller. The utility model is composed of a single chip computer system, a temperature detecting circuit, a quenching detecting circuit, a water level sensor, a digital display circuit, a press key and reset circuit, an alarm circuit, an analogue-to-digital converter, a photoelectric isolation and drive circuit, and a multi-circuit relay. The utility model is characterized in that the temperature sensor is a simple voltage dividing circuit, the structure is simple, and the precision is high; a quenching sensor uses a common horn as the sensor; the vibration generated in combustion is converted into the pulse signal, the monostability is triggered, and the signal indicates whether the water boiler normally combusts or not is obtained. The microcomputer sends out the control instruction through receiving and processing various sensing signals, and controls the operation of the water boiler. The utility model improves the automation degree of the water boiler in pulse combustion, and has safety and convenience.

Description

Micro-computer controller for pulse burning water heating stove

The utility model relates to a kind of microcomputer controller, especially for the automatic controller of pulse-combustion water heater.

The pulse-combustion water heater is a kind of utilization quick gas water-heating furnace of advanced pulse-combustion art designs in the world.Its theory of combustion is: when combustion gas and air enter the combustion chamber after mixing chamber mixes, use spark ignition for the first time, after taking fire, because the gas expansion is closed breather cheek valve, promote flue gas simultaneously and discharge after by heat exchange pipeline.Because action of inertia, make again to form negative pressure the combustion chamber in, so open intake valve again, suck mist once more, and the heat that is produced by previous cycle at once lights, burning is--air-breathing--so repeatedly burns again, periodically continues.This kind combustion furnace, simple in structure, combustion intensity is big, and consumption gas is few, and the thermal efficiency can reach more than 90%, except that having the low advantage of cost, also can reduce the pollution to air.

A kind of like this advanced person's water heater must need the advanced automatic control equipment of a cover to control its operation, with security, the flexibility of guaranteeing its use.

The controller that Japan produces adopts a plurality of relays to do switch control, and its core is called as " attemperator ", comes the opening and closing of control relay contact by it; Temperature detection adopts expensive RTD (pt100).This controller does not have water level and detects inlet, does not have temperature yet and shows the not charged brain of The whole control system.

Task of the present utility model is the automatic controller of a kind of pulse-combustion water heater of design, realizes automatic igniting, the dual control of air feed, automatic water-supply, water temperature detection and water level, water temperature automatically to water heater under the control of computer.

Above-mentioned task has satisfactorily been finished in the utility model and unique technique measure, its concrete structure characteristics are: this controller is by temperature sensor and testing circuit, misfire detector and testing circuit, level sensor, warning circuit, button and reset circuit, A/D converter, the digital display circuit, photoisolator, driver, single-chip microcomputer, latch and memory constitute, the temperature sensing circuit output signal A/D converter of feeding, A/D converter, the misfire detection circuit, key and reset circuit and output signal are delivered to the single-chip microcomputer inlet respectively, the single-chip microcomputer delivery outlet is circuit taking alarm respectively, the digital display circuit, latch, memory, A/D converter and demonstration, the control mouth, photoisolator is connected between computer power and the relay power, show that mouth connects display circuit, controller connects photoelectric isolating circuit, drive circuit and igniter, intake valve, water intaking valve, pairing each road relay switch such as blower fan and condition indication circuit are connected.

This microcomputer controller device is core with the single-chip microcomputer, constitutes a computer controller.Below, as follows to each hardware link division of its formation:

One, temperature detection passage: in order to simplify controller architecture, the simple bleeder circuit that adopts conventional, electric-resistance and semiconductor temperature-measuring thermistor formation is as temperature sensor, its transducing signal A converter of feeding is done the A/D conversion, the A/D transformed value is sent into single-chip microcomputer again and is handled.

Two, water level signal passage: adopt magnetic switch to gather water level signal, magnet places on the float of water storage tank, and switch is placed on tank outer wall, and the float that carries magnet floats with water level, and magnet is switched on or switched off magnetic switch, and microcomputer promptly obtains the SEA LEVEL VARIATION situation in view of the above.

Three, misfire detection circuit: pulse-combustion water heater theory of combustion uniqueness, can not detect combustion case with conventional method, the utility model has designed the unique detection means, is about to common loudspeaker and is close to the furnace wall, the vibration of wall will cause moving of horn coil, produce faint induced voltage.This signal is amplified, just can obtain the pulse signal of series.These pulse signals.These pulses directly trigger a monostable circuit, during water heater work, and monostable maintenance transient state, during shutdown, vibration disappearance, triggerless pulse, monostable its stable state of getting back to.Microcomputer is whether decidable shuts down in view of the above.

Four, output channel: microcomputer output mainly is the several auxiliary reclays of control.The microcomputer output signal is delivered to controller and display, and the control mouth is driver connected through photoisolator, and driver connects each relay, shows that mouth connects charactron.The make-and-break signal of each relay is by latches.On each relay and the negative peak of disappearing diode arranged,, also there is light emitting diode to indicate simultaneously as relay status with the protection driver.Photoelectric isolating circuit is used for eliminating interference.

Five, warning circuit: when being in an emergency, alarm sends chimes of doom, and is mixed with light-emitting diode flash.It adopts the audio frequency blocking oscillator, promotes loudspeaker after amplifying.

Six, keyboard and reset circuit: used key has only three in this controller: start key, purge key and the stop key that resets.Under armed state, press start key, water heater starts automatically, enters automatic control state; Press the purging key, start blower fan 12 seconds, be mainly used in and shut down residual mist and dust in the most combustion chamber of post-purge, purging finishes, and controller is got back to armed state again.Under any state, press stop key, water heater promptly quits work, and is ready; Each executing agency does not all work at this moment, but water temperature shows that as usual the operator can select to start or purge key once more, and in water heater startup operation back, except that stop key, other key is all inoperative.

Owing to taked the above-mentioned structure that comprises single-chip microcomputer; microcomputer technology is applied to the automatic control of water heater; make this controller replace manually-operated substantially; make pulse-combustion water heater automaticity higher; integrated level height not only; good reliability, and volume, weight greatly reduces; the ratio of performance to price is more superior; has the water temperature superelevation; the sound and light of alarm that burner is flame-out can be restarted after stopping working suddenly voluntarily, removes to show water temperature; outside the running status; controller has self diagnostic capability; in case system breaks down, can judge immediately, make water heater be in safe shutdown armed state.

This controller architecture is simple, flexible and convenient operation, has improved the automaticity of water heater greatly, and coming into operation of it will economized on gas, prevent the fouling of main frame water tank, the positive effect of its aspect performance in service life of economic use water heater and prolongation.

Illustrate the utility model below in conjunction with accompanying drawing:

Fig. 1 circuit block diagram

Fig. 2 electrical schematic diagram

This controller is that core is equipped with latch U41 memory under program U3 composition microcomputerized controller with 8031 single-chip microcomputer U1 of MCS-51 series, its integrated level height, and good reliability, volume is little, and is in light weight.

Temperature sensor is made up of RTF and RT, and RTF is a divider resistance, and RT is the semiconductor temperature-measuring thermistor, RTF to choose the electric current that should guarantee by RT enough little, the thermal noise that electric current is caused can be ignored.

A/D converter adopts general successive comparison A/D converter 0809, can be directly and microcomputer interface, and need not add logic.Because its input impedance is very big, the high sensitivity of temperature detecting resistance RT makes that the partial pressure value of sending into A/D is enough, need not amplifier mate, and its precision just can satisfy the control requirement.Find out A/D conversion value and functional relationship of temperature, programming input single-chip microcomputer calculates temperature value by it.

Level sensor adopts magnetic switch, and the RL1 among the power supply reason figure links to each other with water level upper limit switch, and RL2 links to each other with the water level limit switch.Upper limit water level and lower limit level sensor signal are sent into single-chip microcomputer U1 respectively, and microcomputer can obtain the SEA LEVEL VARIATION situation according to the closed situation of magnetic switch.

The misfire detection circuit is made of detector S1, two utmost point operational amplifier U13A, U13B, the monostable U14A that can trigger and peripheral circuit, and U13A, U13B adopt LM324, and U14A adopts 74LS123.Misfire detector is utilized common loudspeaker, cone is close to the furnace wall, vibrations during the stove burning are moved horn coil, produce faint induced voltage, with this signal deliver to U13A, U13B amplifies, and obtains series of pulses, these pulses directly trigger monostable U14A, as long as water heater work just has trigger impulse that it is remained on the transient state; When water heater was shut down, vibrations disappeared, and trigger impulse also disappears, monostable will getting back on its stable state, and microcomputer is that the decidable water heater is in flame-out still running status in view of the above.

Button and reset circuit are made of button KEY1～3, resistance R K1, RK2, RF1, RF2, capacitor C F, and three buttons are respectively start key, purge the key and the stop key that resets.Starting, purge key is to utilize a certain position of 8031 single-chip microcomputer parallel ports to make key scanning.It is low level that key is pressed, and not pressing is high level, and microcomputer judges according to this whether this two key is pressed.When powering on, capacitor C F both end voltage appears at the variation that moment is charged to+discharges behind the 5V voltage, this moment+the 5V pulse is fed to microcomputer RESET end, makes the microcomputer electrification reset.In the middle of program is carried out, press reset key, microcomputer is resetted and the execution of terminator immediately, get back to armed state, reach the shutdown purpose.

Display unit uses two LED charactrons to do the temperature demonstration, and is equipped with the auxiliary respectively switch situation that shows each road relay in light emitting diode LX1～4.This controller utilizes two latch U6, U7 to extend out two parallel ports.Microcomputer need only be sent into the type matrix of sample temperature value this two parallel port can finish demonstration work.

Warning circuit is made of four NAND gate U8, transistor GBS, capacitor C GB, resistance R GB1, RA3, luminous tube LA and loudspeaker S2 with Schmidt's characteristic.The audio signal generator that this four NAND gate is formed can produce intermittently audio signal, this signal and microcomputer P17 hold the signal that presets with after, through the triode amplification, promptly send " enlightening ... enlightening ... " chimes of doom.Simultaneously with light-emitting diode flash.Microcomputer can be controlled alarm unit by the level of control P17.

The interference that produces when the igniting of Pulse Electric igniter, switch electromagnetic valve, startup blower fan is very strong.Microcomputer use+5V power supply, relay use+24V power supply.Adopt photoisolator with two isolated from power, can overcome strong interference.Photoisolator is made of OP1～4 optocoupler and peripheral circuit, and an end joins by latch U5 and microcomputer, and an end links to each other with driver U9.U9 adopts MC1413, links to each other with each road relay switching circuit respectively.

Latch U5 and nor gate U11, U12 are that microcomputer extends out the control mouth, and U5 adopts 74LS273, and U11, U12 adopt 74LS02.Microcomputer provides the make-and-break signal of each relay according to actual operating state, latchs by 273, isolates through photoisolator, makes the actuating of relay after the driver drives.Diode connected in parallel DO1～4 are the negative peak diode that disappears on the relay, can protect driver MC1413 not damaged by the back-pressure of winding.

The installation method of this controller is very simple, need only the link of the link of water heater and controller be connected with the special-purpose stube cable of a random arrangement to get final product.

Claims (10)

1, pulse-combustion water heater microcomputer controller, comprise temperature sensor and temperature sensing circuit, misfire detector and misfire detection circuit, level sensor, flame-out warning circuit, button and reset circuit, digital display circuit and multicircuit relay, it is characterized in that having adopted single-chip microcomputer, A/D converter, show mouth, control mouth and photoisolator, the temperature detection output signal is delivered to AD converter, A/D converter, the misfire detection circuit, the output signal end of button and reset circuit connects the single-chip microcomputer inlet, the single-chip microcomputer delivery outlet is circuit taking alarm respectively, the latch memory, show mouth, control mouth and A/D converter, photoelectric isolating circuit is connected between computer power and the relay power, drive circuit and igniter, intake valve, water intaking valve, each road relay switch such as blower fan and condition indication circuit link to each other.

2,, it is characterized in that temperature sensor is a simple resistor voltage divider circuit according to the described pulse-combustion water heater of claim 1 microcomputer controller.

3,, it is characterized in that misfire detector is common loudspeaker according to the described pulse-combustion water heater of claim 2 microcomputer controller.

4,, it is characterized in that condition indication circuit is that parallel connection one only needs negative peak diode and a light emitting diode on each relay according to the described pulse-combustion water heater of claim 1 microcomputer controller.

5, according to the described pulse-combustion water heater of claim 1 microcomputer controller, it is characterized in that but the misfire detection circuit is made of the monostable of a two-stage single-ended operational amplifier and a repeated trigger, first order amplifier input termination misfire detector--the coil of loudspeaker.

6, according to the described pulse-combustion water heater of claim 1 microcomputer controller, it is characterized in that level sensor is a magnetic switch, magnet places on the float of water storage tank, and switch places tank outer wall, links to each other with single-chip microcomputer.

7,, it is characterized in that single-chip microcomputer adopts 8031 chips according to the described pulse-combustion water heater of claim 1 microcomputer controller.

8,, it is characterized in that warning circuit adopts four NAND gate integrated circuit 74LS132 with Schmidt's property according to the described pulse-combustion water heater of claim 7 microcomputer controller.

9,, it is characterized in that between photoelectric isolating circuit output and multicircuit relay circuit, being connected drive circuit according to the described pulse-combustion water heater of claim 1 microcomputer controller.

10, according to the described pulse-combustion water heater of claim 1 microcomputer controller, it is characterized in that the digital display circuit is made of two LED charactrons and two data latch, the equal order sheet of the input of latch machine data bus, output are connected on the high and low position of LED charactron respectively.

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