JPS6157541B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a water temperature control method for an instantaneous water heater, and by intentionally pulsating the desired set temperature, it provides a pleasant stimulation to the human body, especially when using a shower, and reduces average fuel consumption. The purpose is to measure.

Recently, a proportional control valve that can control fuel continuously has been developed, and a model that combines this with electronic control technology to control the water temperature of a water heater has been released on the market. Instant water heaters, which do not change the water supply temperature, are gaining popularity.

However, humans often find it more comfortable to receive appropriate stimulation at appropriate intervals than to receive a fixed external force; good examples include pine surgery, acupuncture, and moxibustion.

The present invention focuses on this and improves the comfort of using the shower by applying pulsation at a constant cycle to the hot water output from the instantaneous water heater while keeping the average temperature constant.

The explanation will be given below according to the figures.

FIG. 1 shows a control system diagram in which the water heater temperature control device of the present invention is applied to a gas instantaneous water heater. Reference numeral 1 designates a heat exchanger, and water is introduced from an inlet 2, heated by the heat exchanger 1, turned into hot water, and flows out to a hot water supply jack 3.
Illustrated here as a shower head. 4 is a gas burner in which gas flowing from a gas inlet 5 through a proportional control valve 6 is burned. The proportional control valve 6 will be explained using an example using an electromagnetic gas proportional control valve that proportionally controls the flow rate of gas flowing through the electromagnetic coil 7. (A description of the structure of the electromagnetic gas proportional control valve will be omitted here.) 8 is a temperature sensor that detects the temperature of hot water at the outlet of the heat exchanger 1, and here the description will proceed using a negative temperature sensitive resistance element.

Reference numeral 9 indicates a control circuit section, in which the signal from the temperature sensor 8 is compared with the temperature set value 10 by a comparator 11, and the difference signal is amplified by an amplifier 12 to drive the control valve 6. 13 is an astable multivibrator circuit that periodically triggers the monostable multivibrator 14. The monostable multi 14 functions to change the temperature set point for a certain period of time.

Figure 2 A and B show the characteristics, the horizontal axis is time,
The vertical axis shows the hot water temperature. The method shown in FIG. 2A applies a pulse to increase the temperature of the water. Now, when the optimum temperature for shower use is t _c , the conventional constant hot water temperature control method controls the amount of gas combustion so that the temperature becomes t _c . However, according to the method of the present invention, the temperature is normally controlled to be a value t _a lower than t _c , and the temperature is increased to Δt every fixed period T ₁ over a period of time T ₂ . Due to this stimulation of Δt, the human body does not feel lukewarm even when the water temperature is t _a . Also, the temperature of the hot water changes periodically, making the shower extremely pleasant, and it also has a pine surge effect on the skin, which is good for your health. In this case, the average temperature is t _b , which is lower than the conventional t _a , so the amount of combustion is reduced by this amount, resulting in energy savings.

The method shown in FIG. 2B is a method of applying a pulse to lower the hot water temperature, and has the same effect as that shown in FIG. 2A. I will omit the explanation here.

FIG. 3 shows an example of a specific circuit that obtains the characteristics shown in FIG. 2A. A comparator 11 is constituted by a bridge including a temperature detector 8, a temperature setting variable resistor 10, and resistors 15, 16, 17, and 18. Midpoint potentials a and b of the bridge are connected to positive and negative inputs of an operational amplifier 19, respectively.

The output potential c of the operational amplifier 19 is determined according to the ratio between the resistors 20 and 21. Potential c is the emitter potential of the transistor 22, and the current value divided by the emitter resistor 23 is the electromagnetic coil 7 of the proportional control valve 6.
flows to 24 and 25 are base resistances of the transistor 22, and 26 is a diode for absorbing electromotive force of the coil 7.

Here, when the water temperature is low, the resistance value of the temperature sensor 8 is large, so that the potential a<b, so the potential c rises by the value multiplied by the amplification factor of the potential difference between a and b, and the coil current increases. When the temperature of the hot water rises and potential b approaches a, the coil current gradually decreases, reducing the amount of combustion and stopping the temperature rise. In other words, the current is applied to the coil at the point where the amount of combustion and the load are balanced and there is no change in the water temperature. The above is the conventional proportional control type combustion control circuit. The present invention relates to circuit 1
3 and a circuit 14 are added to obtain the characteristics shown in FIG.

Since the circuit 13 is an astable multivibrator circuit and the capacitor 27 is not charged at the beginning of energization, there is no potential at the negative input terminal of the comparator 28. However, since the potential d interposed between the resistors 29 and 30 is applied to the positive input terminal, the comparator 28 outputs a high output, and the potential e becomes close to the power supply voltage. Therefore, the capacitor 27 begins to be charged through the parallel circuit of the resistor 31, resistor 32, and diode 33. When the capacitor 27 is charged and the potential f exceeds the potential d, the output e becomes low and becomes almost zero.
As a result, the charge on the capacitor 27 is transferred to the resistor 31.
is discharged through. By repeating the above, the output e repeats high and low. Because of the presence of the diode 33, the charging time constant of the capacitor 27 is shorter than the discharging time constant, and the output e becomes a rectangular wave with a long low time and a short high time. 32 is a positive feedback resistor for determining hysteresis.

Circuit 14 shows a monostable multivibrator, and a trigger pulse from circuit 13 causes resistance 1 to rise for a certain period of time.
It works to shoot 8. When the potential e is low, a diode 34 is connected to the positive input terminal of the comparator 33.
Since the potential d' through the transistor 35 is applied, the output g is low and the transistor 35 is not conductive. Output e
When becomes high, a potential e' is generated at the positive input terminal of the comparator 33 through the diode 38 interposed by the resistors 36 and 37. At this time, since the design is such that the potential e'>d', the output g becomes high. At this time, even if the output e of the comparator 28 for forming the potential e' by the resistors 39 and 40 returns to low, the comparator 3
The output g of No. 3 remains high. Furthermore, the capacitor 42 begins to be charged through the resistor 41, and the potential d' gradually increases. Eventually, when the potential d'≧e', the output g of the comparator 33 returns to low and waits until the output e of the comparator 28 becomes high again. When the potential g is now high, the transistor 35 is turned on by the resistors 43 and 44, and if the switch 45 is turned on, the resistor 18 is turned off. When the resistor 18 is shorted, the potential a decreases and the potential c increases. In other words, the temperature setting value increases by the amount of resistance 18, increasing the current of the coil current 7 of the proportional valve 6 and increasing the combustion amount. Switch 45 is a selection switch for cases where high temperature is required or for those who prefer constant temperature.

In this embodiment, the astable multivibrator is used to provide a constant period, but the period may be based on some other function. Furthermore, it is also possible to constantly change the time width T ₂ and the temperature difference Δt.

Furthermore, the characteristics shown in FIG. 2B can be easily considered from the circuit example shown in FIG.

As explained above, the temperature control device of the water heater of the present invention goes one step further than the conventional method of keeping water at a constant temperature, and is a system that keeps the average water temperature constant while pulsating, so it is natural especially when used in a shower etc. The water temperature changes pleasantly and occasionally in pulses, which stimulates the skin and is good for health and beauty. Furthermore, since you can feel the same warmth at a lower average hot water temperature than when using a constant hot water temperature, fuel is saved and it is an energy-saving device, which has great industrial value.

[Brief explanation of the drawing]

Fig. 1 is a control system diagram showing an example of a temperature control device for a water heater of the present invention, Fig. 2 A and B are control characteristic diagrams of an applied drawing of the present invention, and Fig. 3 is a circuit diagram showing an example of a specific circuit. be. DESCRIPTION OF SYMBOLS 1... Heat exchanger, 4... Burner, 6... Proportional control valve, 8... Temperature sensor, 9... Control circuit, 10
...Variable resistor for temperature setting (temperature setting value), 13
...astable multivibrator circuit, 14...monostable multivibrator circuit.

Claims (1)

[Claims] 1 A heat exchanger heated by a burner, a temperature sensor that detects the temperature of hot water at the outlet of the heat exchanger, a control circuit that compares and amplifies the signal of the temperature sensor and a temperature set value, and a signal of the temperature control circuit. The control circuit includes a proportional control valve that is driven by and provided in a passage that supplies fuel to the burner and continuously controls fuel, and the control circuit includes a first circuit that varies a temperature set value for a certain period of time; A second drive that periodically drives the circuit.
A temperature control device for a water heater, characterized in that it has a circuit.