JPH0416115Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to a water heater control device.

(Prior art) A conventional water heater control device is shown in Figures 1 and 2.
As shown in the figure, a signal corresponding to the deviation between the hot water outlet temperature and the set temperature detected by a bridge circuit c incorporating a hot water temperature sensor a for detecting the hot water outlet temperature and a variable resistor b for setting the hot water outlet temperature is transmitted. Operational amplification is performed by an operational amplifier d, and the output of the amplifier d is used to generate a heat exchanger e.
By adjusting the opening degree of a proportional control valve h interposed in the fuel supply path g of the burner f that heats the burner f, the combustion amount of the burner f can be controlled proportionally, and the hot water temperature can be controlled to an arbitrary set temperature. or, as shown in Figs. 3 and 4, the water supply temperature and setting detected by a bridge circuit m incorporating a water temperature sensor k for detecting the supply water temperature and a variable resistor l for setting the hot water temperature. A signal corresponding to the deviation from the temperature and a water flow sensor n
The operational amplifier o outputs a signal corresponding to the hot water supply load by multiplying the signal corresponding to the water supply amount detected by By adjusting the opening degree of the proportional control valve s, the combustion amount of the burner q can be controlled proportionally, and the hot water temperature can be controlled to an arbitrary set temperature.
(see Publication No.) is known. Note that j in FIG. 2 indicates the excitation coil of the proportional control valve h, and u in FIG. 4 indicates the excitation coil of the proportional control valve s.

(Problem to be solved by the invention) However, with the above conventional method, if the hot water supply load exceeds the hot water supply capacity, the hot water temperature may not be able to rise to the set value even if the burner is in the maximum combustion state. Occurs often.

(Means for solving the problem) The purpose of the present invention is to provide a device that can control the hot water temperature to a set temperature even in the above case. A combustion controller that proportionally controls the hot water supply temperature to a desired set temperature according to the hot water supply load determined by the deviation between the water supply temperature and the set temperature and the water supply amount, and the amount of water supplied to the heat exchanger. and a water supply amount controller that reduces water according to the deviation when the hot water supply load exceeds the hot water supply capacity, and the combustion controller is equipped with a water temperature sensor for detecting the temperature of the water supply and a water temperature sensor for setting the hot water temperature. a bridge circuit incorporating a variable resistor, a water flow sensor, a signal corresponding to a deviation between the water supply temperature detected by the bridge circuit and a set temperature, and a signal corresponding to the water supply amount detected by the water flow sensor. an electromagnetic proportional amplifier which inputs the output signal from the first operational amplifier and which is interposed in the fuel supply path of the burner. and a first amplifier that causes a current to flow in accordance with the hot water supply load to the excitation coil of the control valve, and the water supply amount controller is configured to take the output signal from the first operational amplifier as an input signal and generate a signal corresponding to the hot water supply capacity. A second operational amplifier outputs a signal according to the difference between both input signals as a setting input signal only when the hot water supply load exceeds the hot water supply capacity, and the output signal from the second operational amplifier is input to the heat exchanger. It is characterized by comprising a second amplifier that flows a current in accordance with the deviation between the hot water supply load and the hot water supply capacity to the excitation coil of a normally open electromagnetic valve inserted in the water supply channel of the water heater.

(Function) The present invention has the above configuration. According to this, when the hot water supply load is lower than the hot water supply capacity, a signal corresponding to the hot water supply load is normally output from the first operational amplifier of the combustion controller, and an electromagnetic proportional The control valve opens more, the combustion amount of the burner increases, and the hot water temperature rises. As a result, the hot water temperature is controlled to the set temperature. However, when the hot water supply load exceeds the hot water supply capacity, the burner Even though it is in the maximum combustion state, the outlet temperature may not rise to the set temperature. In this case, an output signal exceeding the hot water supply capacity is obtained from the first operational amplifier, and therefore an output signal corresponding to the deviation between the output signal and the signal corresponding to the hot water supply capacity is output from the second operational amplifier of the water supply controller. is obtained, the normally open solenoid valve is throttled, the amount of water supplied decreases, and the hot water temperature reaches the set temperature.

Thereafter, when the water heater load falls below the hot water supply capacity, no output is generated from the second operational amplifier, and the normally open solenoid valve returns to its normal fully open state.

(Example) Fig. 5 and Fig. 6 show an example of the implementation of the present invention, and the control device for this water heater controls the combustion amount of the burner 2 that heats the heat exchanger 1 based on the water supply temperature and the set temperature. A combustion controller 3 that proportionally controls the outlet temperature of hot water to an arbitrary set temperature according to the hot water supply load determined by the deviation between the A water supply amount controller 4 is provided which reduces water supply according to the deviation when the hot water supply load exceeds the hot water supply capacity.

To explain this in more detail, the combustion controller 3
is a bridge circuit 7 incorporating a water temperature sensor 5 for detecting the temperature of water supply and a variable resistor 6 for setting the hot water temperature.
Then, a signal corresponding to the deviation between the water supply temperature detected by the water quantity sensor 8 and the bridge circuit 7 and a signal corresponding to the water supply quantity detected by the water quantity sensor 8 are inputted, and both signals are multiplied. A first operational amplifier 9 outputs a signal corresponding to the hot water supply load.
and a first amplifier which inputs the output signal from the first operational amplifier 9 and flows a current according to the hot water supply load to the excitation coil 11a of the electromagnetic proportional control valve 11 interposed in the combustion supply device 10 of the burner 2. Consisting of 12,
The water supply amount controller 4 uses the output signal from the first operational amplifier 9 as an input signal, uses the signal corresponding to the hot water supply capacity as a setting input signal, and controls both input signals only when the hot water supply load exceeds the hot water supply capacity. a second operational amplifier 13 that outputs a signal according to the difference; and an excitation coil 15a of a normally open solenoid valve 15 that receives the output signal from the second operational amplifier 13 and intervenes in the water supply channel 14 of the heat exchanger 1. and a second amplifier 16 that flows a current according to the deviation between the hot water supply load and the hot water supply capacity.

A thermistor was used as the water temperature sensor 5, a pressure sensitive diode was used as the water amount sensor 8, and transistors were used as the first and second amplifiers 12 and 16.

Next, to explain its operation, when the hot water supply load is lower than the hot water supply capacity, a signal corresponding to the deviation between the water supply temperature detected by the bridge circuit 7 and the set temperature and the water supply amount detected by the water flow sensor 8 is generated. A signal is input to the first operational amplifier 9,
Here, both signals are multiplied and the first operational amplifier 9 outputs a signal corresponding to the hot water supply load.
A current corresponding to the hot water supply load is passed through the excitation coil 11a of No. 1, and the electromagnetic proportional control valve 11 increases its opening,
The combustion amount of the burner 2 increases, the hot water temperature rises, and as a result, the hot water temperature is controlled to the set temperature, but when the hot water supply load exceeds the hot water supply capacity, in the conventional system, the burner 2 is in the maximum combustion state. Despite this, the hot water temperature may not rise to the set temperature. In this case, according to the present invention, an output signal exceeding the hot water supply capacity is obtained from the first operational amplifier 9,
The second operational amplifier 13 inputting this output outputs a signal corresponding to the deviation between the hot water supply load and the hot water supply capacity, and the second amplifier 16 inputting this output controls the current flowing through the excitation coil 15a of the normally open solenoid valve 15. The normally open solenoid valve 15, which is normally open, is throttled, the amount of water supplied decreases, and the hot water temperature reaches the set temperature.

Thereafter, when the hot water supply load becomes less than the hot water supply capacity, no output is generated from the second operational amplifier 13, and the normally open solenoid valve 15 returns to its normal fully open state.

(Effect of the invention) As described above, according to the invention, when the hot water supply load exceeds the hot water supply capacity and the hot water supply temperature does not rise to the set temperature during high loads, the water supply amount controller reduces the amount of water supplied to the heat exchanger. As a result, the hot water temperature can always be controlled to the set temperature, and the inconveniences of conventional devices can be reliably eliminated, and the structure is simple and easy to manufacture.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of the conventional device, Fig. 2 is its electric circuit diagram, Fig. 3 is a schematic explanatory diagram of another conventional device, Fig. 4 is its electric circuit diagram, and Fig. 5 is the inventive device. A schematic explanatory diagram showing one example, and FIG. 6 is an electric circuit diagram thereof. 1... Heat exchanger, 2... Burner, 3... Combustion controller, 4... Water supply amount controller, 5... Water temperature sensor,
6... Variable resistor, 7... Bridge circuit, 8...
Water amount sensor, 9...first operational amplifier, 10...fuel supply path, 11...electromagnetic proportional valve, 11a...excitation coil, 12...first amplifier, 13...second operational amplifier, 14... Water supply channel, 15... Normally open solenoid valve, 15a... Excitation coil, 16... Second amplifier.

Claims (1)

[Scope of utility model registration request] Combustion that proportionally controls the combustion amount of the burner that heats the heat exchanger according to the hot water supply load, which is determined by the deviation between the water supply temperature and the set temperature, and the amount of water supplied, thereby controlling the outlet temperature to a desired set temperature. A controller, a water supply amount controller that reduces the amount of water supplied to the heat exchanger according to the deviation when the hot water supply load exceeds the hot water supply capacity, the combustion controller: A bridge circuit incorporating a water temperature sensor for detecting supply water temperature and a variable resistor for setting hot water temperature, a water flow sensor,
Inputs a signal corresponding to the deviation between the water supply temperature detected by the bridge circuit and the set temperature, and a signal corresponding to the water supply amount detected by the water flow sensor, multiplies both signals, and outputs a signal corresponding to the hot water supply load. a first operational amplifier that inputs an output signal from the first operational amplifier and causes a current corresponding to the hot water supply load to flow through an excitation coil of an electromagnetic proportional control valve interposed in the fuel supply path of the burner; The water supply amount controller is configured such that the output signal from the first operational amplifier is used as an input signal, the signal corresponding to the hot water supply capacity is used as a setting input signal, and the water supply amount controller is configured to operate both when the hot water supply load exceeds the hot water supply capacity. A second operational amplifier outputs a signal according to the difference in input signals, and the output signal from the second operational amplifier is input to supply hot water to the excitation coil of a normally open solenoid valve interposed in the water supply channel of the heat exchanger. 1. A control device for a water heater, comprising: a second amplifier that flows a current according to a deviation between a load and a hot water supply capacity.