JPS6235577B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to hot water temperature control for water heaters using gas, oil, electricity, etc. as a heat source, and eliminates the drawback of conventional devices that hot water at the set temperature cannot be obtained when overloaded. The object of the present invention is to provide a new control device that can obtain a desired hot water temperature and has means for notifying the load control state.

This will be explained using a gas water heater as an example.

FIG. 1 is a block diagram of a conventional gas water heater, in which combustion heat in a burner 1 and water are exchanged in a heat exchanger 2 to provide hot water. The temperature controller 3 receives the signal TW from the hot water temperature detector 4 and the signal from the temperature setting device 5.
TWR is input, a predetermined combustion amount is determined from the difference between the TW and TWR, and a control signal is output to the supply heat amount controller 6 to control the hot water temperature. 7 indicates a hot water supply location. Here, the hot water temperature detector 4 may be a thermistor, and the temperature controller 3 may be a thermistor.
PiD controllers etc. are often used.

Figure 2 shows the hot water output W and temperature rise Δ of a gas water heater.
It is a figure showing the relationship with T. The solid line represents the characteristics at the maximum combustion amount. In other words, the maximum combustion amount Q _g
nax , temperature rise ΔT, and flow rate W are as follows, where η is the combustion efficiency, η・Q _{g nax} =W・ΔT...(1), and ΔT=η・Q _{g nax} /W...(2) It is. Therefore, the temperature rise Δ above that indicated by the solid line
T does not exist. For example, when the maximum combustion amount Q _{g nax} and the hot water output amount is W ₁ , the temperature rise ΔT becomes ΔT ₁ as shown in the figure. The temperature controller 3 described above operates effectively when the temperature rise is ΔT=ΔT ₁ and the hot water output amount W is less than W ₁ . If W
>W ₁ , control becomes impossible and the hot water temperature TW cannot reach the set temperature TWR.

In this way, the maximum combustion amount Q _{g nax} limits the water supply amount W that allows the temperature of the hot water to be controlled. This phenomenon is not limited to gas water heaters, but also applies to water heaters using other fuels.

The present invention provides a hot water temperature control device that eliminates the drawbacks seen in the hot water temperature control of the conventional water heater mentioned above.
TWO is obtained, and the convenience of use is increased by notifying the user of the operating status of the water supply amount control device.

FIG. 3 is a block diagram of the gas water heater of the present invention.
The same numbers in FIG. 1 indicate the same parts.
The water flow controller 8 receives a signal from the hot water temperature detector 4.
TW, the signal TWR from the temperature setting device 5, and the output signal of the temperature controller 3 are inputted, and a signal for controlling the water supply amount control device 9 is outputted based on the temperature deviation TER mentioned above. Further, the control signal drives the supply water amount control device 9, and when the water supply amount control device 9 is in a state where the flow rate is reduced from the fully open flow rate, the notification means 10 consisting of a display element such as a lamp, an alarm device, etc. is activated.

When starting to use the gas water heater, the supply water amount control device 9 is initialized so that the maximum flow rate _Wnax can be obtained. If the amount of heat supplied to the water heater is at the maximum even after a certain period of time has passed after the start of use, and the temperature deviation TER remains, the supply water amount control device 9 is operated to reduce the amount of water supplied according to the TER, and the TER The amount of water is controlled so that it approaches zero. Furthermore, if the set temperature is changed during use or the flow rate, which is the load, fluctuates, the amount of water supplied is controlled based on the value of the deviation TER in the steady state after the transient period.
By this operation, hot water at the set temperature can always be obtained, and when the set temperature is lowered during use, the water supply amount can be initialized to the water supply amount limited by the hot water supply point 7.

By the way, the above-mentioned "a certain time after the start of use" and the time until "steady state after the transient period" are as follows.
This is related to the process delay time and the control performance of the temperature controller.

In addition, in the characteristic diagram of flow rate and temperature rise in Fig. 4, the operation of the notification means is such that the supply water amount control device throttles the water amount until W = W ₂ after the start of use, and ΔT = ΔT ₂
It is also very effective to carry out the state at point A, where the temperature is at (TWR), and reduce the amount of water at the hot water supply point 7 in the middle of use, and not operate at point B, where the temperature reaches W ₃ (<W ₂ ). At point B, the combustion amount is not 100% and there is some margin left.

Incidentally, lighting or blinking of a lamp such as an LED, and an alarm such as a buzzer are also effective as means of notification.

As described above, according to the present invention, the amount W of hot water dispensed is always limited to a range in which the temperature of hot water dispensed can be controlled, so that hot water at a desired temperature can be obtained at any time. Furthermore, by having a notification means that notifies the user of the state in which the water supply amount control device is operating, that is, the state in which the water supply amount increase is restricted depending on the hot water supply point, when the user wants the amount of hot water even though the temperature may drop slightly. It has the effect of further improving the convenience of use, such as by recognizing the notification state and lowering the set temperature and allowing the water heater to be used in hot water supply priority mode.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional gas water heater, Fig. 2 is a characteristic diagram showing the relationship between hot water output amount and temperature rise of the gas water heater of Fig. 1, and Fig. 3 is an embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a gas water heater, and FIG. 4 is a characteristic diagram showing the relationship between the amount of hot water coming out and the temperature rise during water amount control. 3... Temperature controller, 4... Hot water temperature detector, 5
... Temperature setting device, 6 ... Water heater supply heat amount controller,
8... Water flow rate controller, 9... Supply water flow rate control device, 1
0...Notification means.

Claims (1)

[Claims] 1 Water heater outlet temperature detector, temperature setting device,
a temperature controller that outputs a signal that controls the amount of heat supplied to the water heater by engaging with the difference (TER) between the signal of the temperature setting device and the signal of the hot water temperature detector; and hot water that responds to the output of the temperature controller. a water quantity controller that outputs a water quantity control signal depending on the temperature deviation (TER), and a supply that controls the supply of water to the water heater in response to the output of the water quantity controller. 1. A water heater control device comprising: a water flow rate control device; and a notification means for notifying a state in which the supply water flow rate is reduced from a fully open flow rate due to the operation of the supply water flow rate control device.