JPS6252317A - Kerosene hot water - Google Patents

Abstract

PURPOSE:To make possible to supply hot water with stable desired temp. by controlling proportionally the current flowing time of a heater in such a manner that a control value is determined after a detected temp. and a set temp. have been compared and the control value is synchronized with the frequency of a commercial power source at every divided scheduled time. CONSTITUTION:At a vaporizer comprising a heater 4 therein, fuel oil is heated and vaporized and temp. of the vaporizer is detected by a temp. sensor 8. A controller consisting of a microcomputer 24 comprises a processing means which calculates the control value after the detected temp. by the temp. sensor 8 and the set temp. are compared, a frequency dividing means which divides frequency of a commercial power source at every scheduled time, and a control means which synchronizes the frequency obtained at every interval time divided by said frequency means with then control value obtained by the processing means and then controls the current flowing time of the heater 4. As a result, the stable temp. control of the vaporizer is possible and also the generation of noises is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an oil water heater, and more particularly to an oil water heater that heats and vaporizes fuel by a heater attached to a militarizer and burns it in a burner.

(Prior Art) An example of a conventional oil water heater is shown in FIG. In Figure 6, 1
is a burner, 2 is a fuel tank, and 3 is a vaporizer. The vaporizer 3 is preheated by operating a heater 4 installed in the vaporizer 3, and after the preheating is completed, the fuel in the fuel tank 3 is pumped into an electromagnetic pump. 5 into the vaporizer 3, the fuel oil is heated and vaporized in the vaporizer 3, the vaporized gas is supplied to the burner 1 by the electromagnetic jet valve 6, and the vaporized gas is ignited by the spark plug 7 to be combusted. , which operates as an oil water heater.

In this case, the heater 4 installed in the vaporizer 3 is controlled based on a circuit as shown in FIG. - That is, a control transformer 9 is connected to the heater 4 attached to the vaporizer 3, a rectifier 10 for AC-DC conversion is arranged on the output terminal side of the control transformer 9, and a smoothing condenser is connected to the output terminal of the rectifier 10. -11, a current limiting resistor 12, and a Zener diode 13 for low voltage circuit are connected in parallel, and a thermistor 8 attached to the vaporizer 3 between the current limiting resistor 12 and the Zener diode 13 and a reference voltage setting resistor are connected in parallel. 14 and temperature setting resistors 15 and 16 are connected in parallel, and the positive input terminal of IC 17 and the negative input terminal of IC 17 are connected between the thermistor 8 and the reference voltage setting resistor 14 and temperature setting resistor 13.14. The output terminal of the IC is connected to the base of the transistor 18, and the relay 19 is connected to the collector of the transistor 18.

When the temperature of the vaporizer 3 reaches or exceeds the set temperature, the input voltage V, V- to the ICl7 becomes V->V, the output signal of the IC17 becomes rLJ, the transistor 18 is turned off, and the relay 19 is turned off. The power supply to the heater 4 is then stopped. On the other hand, if the temperature of the vaporizer 3 falls below the set temperature, the input voltage V,, V- to the IC 17 becomes V+>V-, and I
The output signal of C17 becomes rHJ, transistor 1B becomes ONL, relay 19 becomes ON, and energization to heater 4 is started.

In this case, in order to obtain stable combustion with burner 1,
It is important to stably supply power to the heater 4, stabilize the temperature of the vaporizer 3, and keep the internal pressure of the vaporizer 3 constant.

(Problem to be Solved by the Invention) However, in this conventional oil water heater, the temperature of the vaporizer 3 and the set temperature are compared and the relay 19 linked to the transistor 18 is turned on and off. , since the energization of the heater 4 is controlled, Fig. 8(a), (
As shown in b), there is a delay in the energization control of the heater 4, and as a result, the temperature control range of the vaporizer 3 becomes large and the internal pressure of the vaporizer becomes unstable, making it difficult to stabilize the desired hot water temperature. The problem was that it was not possible to obtain In addition, FIG. 8(a) is a diagram for explaining the temperature change of the vaporizer of a conventional oil water heater, and FIG. 8(b) shows the energization time to the heater attached to the vaporizer. It is a diagram.

In addition, in this conventional oil water heater, electricity is turned on and off to the heater 4 by turning on and off the relay 19 that is linked to the transistor 18.
Another problem is that noise is generated when the heater 4 is turned on and off, and as a result, a separate circuit must be provided to prevent the noise.

(Objective of the Invention) The present invention has been devised in view of the above problems, and has the following objects: 1. In addition to stable temperature control of the vaporizer,
The objective is to provide an oil water heater that does not generate noise.

(Means for Solving the Problems) The oil water heater of the present invention includes a vaporizer equipped with a heater for heating and vaporizing fuel, a temperature sensor that detects the temperature of the vaporizer, and the temperature sensor. a calculation means for calculating a control value by comparing the detected temperature and a set temperature; a frequency division means for dividing the frequency of the commercial power supply into predetermined time intervals; and a controller comprising control means for proportionally controlling the energization time of the heater by synchronizing the control value obtained by the calculation means.

(Example) Hereinafter, the present invention will be explained in detail based on the attached FIGS. 1 to 5. Note that the same parts as in the conventional example are given the same reference numerals.

FIG. 1 is a circuit diagram showing a method of controlling a vaporizer of an oil water heater according to the present invention, where 4 is a heater attached to the vaporizer to heat and vaporize fuel, and 8 is a heater that detects the temperature of the vaporizer. This is a temperature sensor consisting of a thermistor, etc.

The thermistor 8 includes a resistor 2 for setting a reference voltage.
It is directly read in series with 0 and connected in parallel with 9 voltage dividing resistor 21. This voltage dividing resistor 21 is the thermistor 8
It has the effect of linearizing.

Between the thermistor 8 and the reference voltage setting resistor 20,
The positive terminal of the amplifier (or attenuator) 22 is connected.

The resistors 28 and 29 determine the amplification factor of the amplifier 22. The output terminal of the amplifier 22 is connected to the A/D input 24a of the microcomputer 24 via a protective resistor 23, and an overvoltage prevention device is connected between the protective resistor 23 and the AID input 248 of the microcomputer 24. A Zener diode 25 for use is connected.

The microcomputer 24 is provided with a power frequency input terminal 24b and an output terminal 24c. A light emitting diode 25 is connected to the output terminal 24c, and the light emitting diode 25 converts an electrical signal into an optical signal and drives the phototriac 26. The photo triac 26 converts the optical signal into an electric signal, drives the diac 27, and turns on the heater 4.
, turns OFF. Note that the phototriac 26 is
A phototransistor may be used instead.

The controller consisting of the microcomputer 24 includes a calculating means for calculating a control value by comparing the temperature detected by the thermistor 8 and a set temperature, and a frequency dividing means for dividing the frequency of the commercial power supply at predetermined intervals. and control means for proportionally controlling the energization time of the heater 4 by synchronizing the control value obtained by the calculation means with the frequency within each time divided by the frequency division means.

That is, as shown in the block diagram in FIG. 2, the temperature of the vaporizer is detected by a thermistor 8, and the output of the thermistor 8 is linearized in order to be input to the microcomputer 24. A/D conversion. The set temperature and frequency division time of the vaporizer are set in the ROM of the microcomputer 24 (7). A CLOCK signal for driving the microcomputer 24 is input from the commercial power supply, and the CP of the microcomputer 24 is input.
The control value is determined by comparing the temperature detected by the thermistor with the set temperature at U, and the frequency of the power supply is sequentially divided by the time set in the ROM, and the control value is synchronized to the frequency within each divided time. and send it to the output circuit, heater 4
Proportional control of power supplied to

FIG. 3 is a diagram showing the relationship between power supply frequency and power control. For example, among the frequency peaks divided into 120 frequencies at intervals of 1.2 seconds, the control value of the first stage is 6/1.
If it is 20%, power is supplied to the heater 4 for six times at the frequency peak of the power supply. Further, if the control value of the next stage is 4/120%, power is supplied to the heater 4 only for four peaks of the frequency of the power supply. Similarly, the electric power supplied to the heater 4 is proportionally controlled by sequentially supplying electric power to the heater 4 for a corresponding period at the frequency peak of the power supply according to the control value and controlling the energization time to the heater 4. do.

FIG. 4 is a diagram showing the relationship between control output and electric energy.

vl is the temperature of the vaporizer, - is the electric energy, vl is the set temperature, and Vb "' V- indicates the proportional band. The power ff1W is controlled at the set temperature v8, for example, 60/120%,
controlled at 120/120%, V, TeO/120
Controlled by %.

FIG. 5 is a diagram showing changes in temperature of the vaporizer when the temperature of the vaporizer is controlled by a controller having the circuit shown in FIG. Although the vaporizer 3 exhibits slight over-shorting and under-shorting at the beginning of heating, it exhibits extremely stable temperature characteristics thereafter.

(Effects of the Invention) Thus, according to the oil water heater of the present invention, the temperature detected by the temperature sensor and the set temperature are compared to determine the control value, and the frequency of the commercial power source is divided at predetermined intervals. Since the control value is synchronized to the frequency of each divided time to proportionally control the energization time of the heater, it is possible to control the energization of the heater in immediate response to changes in the temperature of the vaporizer, and also to control the energization of the heater immediately. It is possible to provide an oil water heater that can perform stable temperature control and thereby stably obtain a desired hot water temperature.

Further, according to the oil water heater of the present invention, since the heater is energized and controlled according to the frequency of the commercial power source, it is possible to provide an oil water heater that can perform power control without generating noise. .

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing the method of controlling the vaporizer of an oil water heater according to the present invention, Fig. 2 is a block diagram of the same, Fig. 3 is a diagram showing the relationship between frequency and power control of the present invention, Fig. 4 is a diagram showing the relationship between the control output and the amount of electric power of the present invention, FIG. 5 is a diagram showing the temperature change of the vaporizer of the present invention, FIG. 6 is a diagram showing the structure of a conventional oil water heater, and FIG. is the same control circuit diagram, Fig. 8(a),
(b) is a diagram showing the relationship between the temperature change of the vaporizer of the conventional oil water heater and the energization time to the heater. 1... Burner 3... Vaporizer 4... Heater 8... Temperature sensor patent applicant (
663) Kyocera Corporation ■ o t (time)

Claims (1)

[Claims] A vaporizer equipped with a heater for heating and vaporizing fuel, a temperature sensor that detects the temperature of the vaporizer, and a comparison between the temperature detected by the temperature sensor and a set temperature. a calculation means for calculating a control value; a frequency division means for dividing the frequency of the commercial power source into predetermined time intervals; and a frequency division means for synchronizing the control value obtained by the calculation means with the frequency for each time divided by the frequency division means. A controller comprising a control means for proportionally controlling the energization time of the heater, and an oil water heater.