JPS6229881Y2 - - Google Patents

Description

[Detailed description of the device] This device relates to an instantaneous water heater that controls a gas control valve and a water volume control valve in response to the temperature difference between a target temperature set by a water temperature setting means and a detected temperature detected by a water temperature sensor.

In general, with instantaneous water heaters, it takes some time from when the faucet is opened until the desired temperature is actually obtained. There was a problem that the hot water flowing out of the vessel was wasted. This is especially true when the temperature of the water supplied to the water heater is low or when the desired temperature is high. In addition, when the required amount of hot water is relatively large and there is a large temperature difference between the temperature of the water supplied to the water heater and the desired target temperature, the heating capacity of the gas burner is limited. There was a problem in that although the same amount of hot water could be drawn as the set amount, the hot water temperature would be lower than the target temperature. In addition, if you use a constant flow valve to keep the amount of hot water within the gas burner's capacity, the amount of hot water can be increased even though the gas burner has excess capacity when the hot water temperature is low. I had a problem with it disappearing.

The present invention was developed to solve these problems of the conventional example, and it shortens the time from opening the faucet until the desired target temperature is obtained, and also shortens the time required to reach the target temperature. This instant water boiler reduces the amount of water that is wasted in the process, and also makes the most effective use of the gas burner's capacity when the required amount of hot water is relatively large and the desired target temperature is high. The purpose is to provide equipment.

The configuration of the present invention will be described below with reference to illustrated embodiments. FIG. 1 shows a system diagram of an instantaneous water heater according to an embodiment of the present invention, in which a heat exchanger 2 heated by a gas burner 1 is connected to a heat exchanger 2 that is heated by a gas burner 1, and a heat exchanger 2 that is heated by a gas burner 1 is connected to a heat exchanger 2 that is heated by a gas burner 1. The water is continuously heated and discharged as hot water. The amount of hot water taken out from the heat exchanger 2 can also be manually controlled by a tip kettle (not shown) provided on the side of the tap. 4 is a solenoid valve for the gas burner 1, 5 is a governor for keeping the secondary gas pressure constant regardless of the primary gas pressure, and 6 is a gas control valve for controlling the amount of gas supplied. The gas control valve 6 and the water flow control valve 3 are designed to be able to control the gas supply amount and water supply amount, respectively, by electrical input signals, and thereby control the temperature of hot water. . FIG. 2 shows a schematic circuit diagram of the control circuit. In the figure, 7 is a variable resistor serving as a hot water temperature setting means, and 8 is a thermistor constituting a hot water temperature sensor. This thermistor 8 is provided on the outlet side of the heat exchanger 2, as shown in FIG. A resistor R1 is connected in series with each of the variable resistor 7 and the thermistor ₈ serving as a hot water temperature sensor, so that the power supply voltage V is divided into voltages. Reference numeral 9 denotes a differential amplifier consisting of transistors Q ₁ and Q ₂ , and when the value of variable resistor 7 and the value of thermistor 8 are equal to each other, no output voltage appears between output terminals a and b. Next, when the resistance value of the variable resistor 7 is lowered and the target temperature is set higher, the resistance value of the thermistor 8 does not change until the hot water temperature actually changes, so the output terminal a,
An output voltage appears between b. This output voltage corresponds to a comparison temperature difference ΔT obtained by subtracting the detected temperature detected by the thermistor 8 from the target temperature set by the variable resistor 7. Therefore, the above output voltage generated between output terminals a and b is
This is input to the hot water temperature control means 10 that electrically controls the gas control valve 6 and the water flow control valve 3. The hot water temperature control means 10 includes a reference voltage generation circuit 11.
is connected, and the output voltage from the differential amplifier 9 is compared with a predetermined reference voltage, and the control operations of the gas control valve 6 and the water flow control valve 3 are switched depending on the magnitude relationship. Figure 3 shows the control operation. In the figure, the horizontal axis shows the change in the comparative temperature difference ΔT obtained by subtracting the detected temperature from the target temperature, and the vertical axis shows the water volume for the solid line. The broken lines indicate changes in the amount of water supplied by the control valve 3, and the broken lines indicate changes in the amount of gas supplied by the gas control valve 6, respectively. First, when the comparative temperature difference ΔT is smaller than the reference value ΔT ₁ , the water flow control valve 3 is fully opened and the gas control valve 6 is controlled to increase the gas supply amount as the comparative temperature difference ΔT increases. It is. Next, when the comparison temperature difference ΔT is between the reference values ΔT ₁ and ΔT ₂ ,
The gas control valve 6 is fully opened to maximize the amount of gas supplied, and the water amount control valve 3 is controlled to decrease the amount of water supplied as the comparative temperature difference ΔT increases. Furthermore, the comparison temperature difference ΔT is the reference value Δ
If it is larger than T ₂ , the gas control valve 6 is fully opened to maximize the gas supply amount, and the water flow control valve 3 is closed.
The amount of water supplied should be minimized.

Since the present invention is configured as described above, when the faucet is open and the hot water temperature is still low, the comparative temperature difference between the target temperature and the detected temperature is large, so the gas control valve is fully opened and the water flow is reduced. Since the amount of water supplied by the control valve decreases, the hot water temperature rises rapidly, which has the advantage that the hot water temperature rises quickly and the amount of water to be discarded is reduced. Since the amount of hot water automatically increases as the water rises, it has the advantage of being extremely easy to operate. Furthermore, in cases where the required amount of hot water is relatively large and the user leaves the pot fully open, if the temperature difference between the water temperature and the target temperature is large, the temperature may exceed the heating capacity of the gas burner. Since the amount of hot water dispensed can be automatically limited, the hot water temperature is given priority over the amount of hot water dispensed, and hot water at an appropriate temperature can always be supplied, which has the advantage of significantly improving the hot water dispensing characteristics of the water heater. It is something that you have.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an embodiment of the present invention, FIG. 2 is a circuit diagram of the same, and FIG. 3 is an explanatory diagram of the same operation. 1 is a gas burner, 2 is a heat exchanger, 3 is a water flow control valve, 6 is a gas control valve, 7 is a variable resistor, 8 is a thermistor, 9 is a differential amplifier, and 10 is a hot water temperature control means.

Claims (1)

[Scope of utility model registration request] A gas control valve that controls the amount of gas supplied to the gas burner, a heat exchanger that converts cold water heated by the gas burner into hot water, a water flow control valve that controls the amount of water supplied to the heat exchanger, and a water flow control valve that controls the amount of water supplied to the heat exchanger. a hot water temperature sensor for detecting the outlet temperature of the hot water; a comparison means for subtracting the detected temperature detected by the hot water temperature sensor from the target temperature set by the hot water temperature setting means to obtain a comparative temperature difference; When the comparison temperature difference is below the reference value, the water flow control valve is fully opened to increase the amount of gas supplied by the gas control valve in accordance with the increase in the comparison temperature difference, and when the comparison temperature difference is above the reference value, the gas control valve is fully opened to reduce the comparison temperature. An instantaneous water heater comprising a hot water temperature control means for controlling a water flow rate control valve to reduce the amount of water supplied according to an increase in the difference.