JPS6235575B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to hot water temperature control for water heaters using gas, oil, electricity, or the like as a heat source.

First, a conventional example 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 TWO 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 TWO 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.

FIG. 2 is a diagram showing the relationship between the hot water output amount Q _L of the gas water heater and the temperature rise ΔT. 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 Q _L are as follows, where η is the combustion efficiency, η・Q _{g nax} =Q _L・ΔT ...(1), and ΔT=η・Q _{g nax} /Q _L ... …(2). Therefore, the temperature rise Δ above that indicated by the solid line
T does not exist. For example, when the maximum combustion amount is Q _{g nax} and the hot water output amount is Q _L1 , 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 Q _L is equal to or less than Q _L1 . If Q _L >Q _L1 , this becomes impossible, and the hot water temperature TWO cannot reach the set temperature TWR.

In this way, the amount of hot water Q _L that can control the hot water temperature is limited by the maximum combustion amount Q _{g nax} . 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 described above.
One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 is a block diagram of the gas water heater of the present invention.
The water flow rate controller 8 inputs the signal TWi from the inlet water temperature detector 9 that detects the temperature of the water flowing into the heat exchanger 2 and the signal TWR from the temperature setting device 5, and outputs a signal that controls the supply water flow rate control device 10. are doing. Components with the same numbers as those in FIG. 1 are devices having the same functions. When starting to use a gas water heater, the supply water flow control device 10 is initially set according to a predetermined control sequence so as to obtain the maximum flow rate Q _Lnax , and then the temperature setting device signal TWR and the inlet water temperature signal TWi are set.
At the point when is detected, the difference between them ΔT _R =TWR−
TWi is determined, and based on the characteristics shown in FIG. 2, a control signal is output to the device 10 to reduce the amount of water supplied to the flow rate Q _R where ΔT = ΔT _R at the time of maximum combustion. . In addition, since changes in the set temperature often occur when using a water heater, the current position of the water supply flow rate control device 10 is held in the memory within the water flow rate controller 8, and when the set temperature is newly changed, It controls the supply water amount control device 10.

Further, reference numeral 11 denotes a hot water supply capacity setting device, which sends a signal to the water flow controller 8 when switching the burner 1 capacity, corresponding to the combustion capacity of the burner 1 often used in water heaters. In other words, since the hot water supply capacity curve shown in FIG. 2 differs depending on each burner 1, the control signal to the water supply amount control device 10 also needs to correspond.

As described above, according to the present invention, the amount of hot water Q
Since _L is always limited to a range where the hot water temperature can be controlled, hot water at the desired set temperature can be obtained.
In addition, since the inlet water temperature TWi and the set temperature TWR are obtained as a signal at the same time as the water heater starts to be used, it is possible to immediately operate to limit the maximum supply water volume that can be temperature controlled based on the characteristics of the water supply flow rate control device, and the hot water temperature control performance is improved. The above also has excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of a conventional gas water heater, Fig. 2 is a diagram showing the relationship between the amount of hot water output and temperature rise of the gas water heater shown in Fig. 1, and Fig. 3 is a diagram showing an embodiment of the present invention. It is a block diagram applied to a gas water heater. 3... Temperature controller, 4... Hot water temperature detector, 5
... Temperature setting device, 6 ... Supply heat amount controller, 8 ...
Water flow rate controller, 9...Incoming water temperature detector, 10...Supplied water flow rate control device, 11...Hot water supply capacity setting device.

Claims (1)

[Scope of Claims] 1. An inlet temperature detector for water flowing into a water heater, an outlet temperature detector for hot water coming out of the water heater, a temperature setting device for the water heater, a signal from the temperature setting device, and a temperature sensor for the hot water coming out from the water heater. a temperature controller that outputs a signal for controlling the amount of heat supplied to the water heater based on a difference in the signals of the temperature detector; a supply amount controller that controls the amount of heat supplied to the water heater in response to the output of the temperature controller; A water flow rate controller that outputs a signal for controlling the supply water volume according to the difference between the signal of the water input temperature detector and the signal of the temperature setting device, and a water supply volume control device that is controlled by the output of the water volume controller. A water heater control device, wherein a signal is output from the water flow rate controller in order to drive the supply water flow rate control device in advance at the time when an incoming water temperature signal and a setter temperature signal are detected. 2. The water heater control device according to claim 1, characterized in that a hot water supply capacity setting device is coupled to a water flow rate controller.