JPS5833053A - Controlling device of water heater - Google Patents

Abstract

PURPOSE:To enable to supply constantly a desired quantity of hot water at a predetermined temperature. CONSTITUTION:A controler 6 for controling the amount of heat supplied to a burner and a controler 10 for controling the quantity of feed water are controled in such a manner that the signal from a detector 4 for detecting the temperature of hot water from a heat exchanger 2 is inputted to a temperature controler 3 and a water quantity controler 8 and the difference between the signal from the detector 4 and the set temperature signal from a temperature setting device 5 is operated. In this case, the flow rate of feed water is made maximum at the time of using the water heater and the quantity of feed water is reduced in proportion to the above mentioned temperature difference from the time when a constant temperature controling condition is reached. Further, when the hot water is stored in a hot water storage device 1, the set value from a total feed water quantity setting device 9 is compared to an integrated value of the quantity of feed water in the water quantity controler 8 and if both values become equal to each other, the supply of feed water is interrupted.

Description

[Detailed Description of the Invention] The present invention relates to the hot water outlet temperature control of water heaters using gas, oil, electricity, etc. as heat sources, and eliminates the disadvantage of conventional devices that the set hot water temperature cannot be obtained when the load is overloaded. The purpose of the present invention is to provide a compact control device that can obtain a hot water temperature of 2,000, and supply the amount of hot water desired by the user according to instructions from a setting device.

The explanation will be given below using a gas water heater as an example.

FIG. 5 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 signal TW from the hot water temperature detector 4 is sent to the temperature controller 3.
O and the signal TWR from the temperature setting device 6 are input, a predetermined combustion amount is determined from the deviation TER=TWR-TWO, and a control signal is output to the supply heat amount controller 6 to control the outlet hot water temperature.

7 indicates a hot water supply location, and there may be multiple locations. here,
The hot water temperature detector 4 and L/7C are thermistors, and as the temperature controller 3, a PiD controller or the like is often used.

FIG. 4 is a diagram showing the relationship between the hot water output amount FW of the gas water heater and the temperature rise ΔT. The solid line in the figure represents the maximum combustion amount Q and the characteristics in the construction. That is, the maximum combustion amount Q2fn
,! If the combustion efficiency is η, then the temperature rise △T and the flow rate FW are η・Qt ma! = FW・△T ・・・・・・
...(1) 3·°-di, and the following relationship holds. Therefore, there is no temperature increase beyond that indicated by the solid line in FIG. For example, maximum combustion amount Q7
If the amount of hot water discharged is Fwl, the temperature m&X rise will be △T1 as shown in the figure.

The above-mentioned temperature controller 3 sets the set value TWR by the temperature setting device.
The difference between and the water inlet temperature TWi, that is, the temperature rise value △T is △T
1, it operates effectively when the amount of hot water FW is less than FWl. If FW >'W1, control is impossible and the hot water temperature TWO cannot reach the set temperature TWR.

In this way, the maximum combustion amount Qf maw limits the amount of hot water FW whose hot water temperature can be controlled.

This phenomenon is not limited to gas water heaters, but also applies to water heaters using other fuels. When using a conventional water heater like this, for example, when pouring hot water into a bathtub, it is necessary to mix high-temperature water and cold water.Initially, the amount of hot water must be adjusted at the hot water inlet to obtain the appropriate water temperature. There are ways to restrict the amount of hot water, but when using the bathtub in multiple locations, you need to control the amount of hot water at a hot water supply point other than the bathtub.The hot water temperature fluctuates rapidly, making it difficult to obtain the desired amount of hot water at the desired temperature. there were.

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, and is capable of constantly supplying hot water at a set temperature, and also according to the signal of the total water supply amount setting device. It is possible to supply the desired amount of hot water.

FIG. 1 is a block diagram of a gas water heater of the present invention.

Devices with the same numbers as in FIG. 5 are devices having the same functions. The water flow controller 8 receives a signal T from the hot water temperature detector 4.
WO, the signal TWR from the temperature setting device 6, and the signal TOTW from the total water supply amount setting device 9 are input, and a signal depending on the temperature deviation TER=TWR−TWO mentioned above is output 4.
The supply water amount control device 10 is controlled. When starting to use the water heater, set the device 1 so that the maximum flow rate Fwmax can be obtained.
0 is initialized, and when the deviation TER is equal to or greater than a predetermined value when the hot water temperature control reaches a steady state, the value is set to 5 according to the TER.
- Operate the supplied water amount control device 10 to reduce the amount of water supplied, and control the amount of water so that TER approaches zero. When the hot water temperature control reaches a steady state, this becomes a problem especially in systems where the process to be controlled has a large delay, and a certain period after the start of use can be determined as a transient state using a timer element.

The state of this control is shown in FIG. (&) , (
b) shows the changes in the supply water amount FW and the hot water outlet temperature TWO with respect to the elapsed time after the start of use, respectively, and tl
It is determined that the steady state is reached at this point, and the flow rate is set to FW based on the deviation TER.
It can be seen that the outlet temperature approaches the set temperature due to the change to maw -FWl.

The flow rate operation amount according to the deviation TER may be changed in small steps in small steps, but the temperature convergence time can be shortened by determining the target value FW from the characteristics shown in Figure 4 and moving it all at once. I can do it.

In addition, in a steady state, when the amount of heat supplied is not the maximum frmx and the amount of water supplied is not the maximum value of Fwma!, the water supply amount control device 1o is operated to increase the amount of water supplied, P! Make sure to obtain hot water at the set temperature at maximum flow rate.

Furthermore, reference numeral 11 in FIG. 1 indicates a water storage device such as a bathtub, and hot water at the set temperature described above is supplied to a certain amount according to the signal from the total water supply amount setting device 9. That is, the amount of water supplied is integrated by the water amount controller 8, and when it becomes equal to the set value, the water amount controller 10 is operated in the direction of closing. Further, if the device 10 does not have a closing function, the user may be notified by using a notification means such as a buzzer or a lamp. Furthermore, it goes without saying that even for products with a closing function, it is possible to improve the usability by using the above-mentioned notification means for notifying the end of supply.

Here, regarding the integration of the amount of supplied water, that is, the integration of the amount of supplied water at the set hot water temperature, if the amount of supplied water is less than the maximum value of the water supply amount control device due to flow regulation at the hot water supply point, in some cases, it is in a steady state. By detecting the control signal for the amount of heat supplied to the water heater, it is possible to convert and integrate the actual flow rate in conjunction with the characteristics shown in FIG. Furthermore, when using a large-capacity water heater such as a bathtub, the process response delay in a normal water heater is so short that it can be ignored, but it is also possible to perform compensation calculations during transient times.

Next, a specific embodiment of the present invention will be explained with reference to FIG. Here, an example will be given in which the microconbeater 12 is used for various calculations and sequence control, and TER.

The intake of TOTW and the driving of the temperature controller and water flow controller will be described. 4.5, 6, 9° 1o in the figure indicate a thermistor as a hot water temperature detector, a temperature setting device, a supply heat amount controller, a supply total water amount setting device, and a supply water amount control device, as described above.

First, the acquisition of the temperature deviation TER will be explained. Set temperature T
WR is input to the operational amplifier 15 via the resistor 14 as a divided voltage vTWR of the variable resistor of the temperature setting device 6 and the resistor 13 connected in series.

Further, the outlet hot water temperature TWO is applied to the same human power section as vTWR of the aforementioned operational amplifier 16 via a resistor 17 as a partial voltage vTWO between the thermistor 4 and a resistor 16 connected in series. This operational amplifier 16 forms a so-called adder, and its reference potential is determined by the partial voltage of resistors 18 and 19, and is determined by the resistor 20 that determines the amplification factor. lvrwo and v
The difference in TWR appears as an output and serves as an inverting input to the comparator 210 in the next stage. This comparator 21 A/D converts the TERO value, that is, the potential-converted vTER, and outputs it as the input P1 of the microcomputer 12, and the reference input side is as follows.
This is the output of the D/A converter 22 controlled by the microcomputer output section P3. In this way, the microcomputer takes in the deviation TER.

The output to the supply heat amount control device calculated from the above-mentioned deviation TER according to the PiD control calculation method, for example, is output to the analog switch 23 and the drive unit 24 controlled by the microcomputer output P4 from the D/A converter 22 in this example. Via
It is transmitted to the supply heat amount control device 6. Said switch 2
3 serves as a selector that does not share the D/A converter for input and output.

Further, the variable resistance of the total water supply amount setting device 9 is a series resistance 26.
It is input to the comparator 26 as the partial pressure vTOTW,
Like TΣR, it is D/A converted and becomes microcomputer-powered P2.

Page 9 Next, in the water flow rate control of this example, an output signal is generated to drive the supply water flow rate control device 10 for a predetermined time calculated from the TER. When restricting the flow rate, the microcomputer output P6 is set to the LOW level, the transistor 28 is turned on via the resistors 26 and 27, and the relay 29 is driven to energize the motor coil 30 that controls the flow rate in the direction of restriction. The relay contact 31 is made conductive. The rotation angle of the motor is determined by the time during which B is conductive, and drives the water supply amount control device 1o. When increasing the flow rate by similar operating means, resistor 32.33° transistor 34
．． The relay contact 37 is closed in order to energize the motor coil 36 via the relay R (35).

By the way, the arithmetic unit serving as a water flow rate controller controls the water volume so that TER approaches zero, and also controls the supply water flow rate to stop the supply of hot water as described above in response to the signal TOTW from the total supply water flow rate setting device 9. 1o is closed,
They also use means of notification.

10. As described above, according to the water heater control device of the present invention, the hot water flow rate FW is always limited to a range where the hot water temperature can be controlled, so it is possible to obtain hot water at the desired temperature at any time. In addition to the above effects, it is possible to store the desired amount of hot water, and it is possible to provide a very convenient function, especially when taking a bath.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a control circuit for a gas water heater showing an embodiment of the present invention, and FIGS. 2(a) and (b) are response characteristic diagrams of hot water output amount and hot water temperature, respectively, by the control device of the present invention. , 3rd
Figure 4 is a specific circuit diagram of the present invention, Figure 4 is a characteristic diagram showing the relationship between the hot water output amount and temperature rise of a gas water heater, and Figure 5 is a configuration diagram of a conventional gas water heater. 3... Temperature controller, 4... Hot water temperature detector, 5... Temperature setting device, 6... Supply heat amount controller, 8... ...Water flow controller, 9...
- Total supply water amount setting device, 1o...Supply water amount control device.

Claims (1)

[Claims] The hot water temperature detector of the water heater, the temperature setting device, and the difference between the signal of the temperature setting device and the signal of the hot water temperature detector (TER)
a temperature controller that outputs a signal for controlling the amount of heat supplied to the water heater depending on the amount of heat supplied to the water heater; a controller that controls the amount of heat supplied to the water heater in response to the output of the temperature controller; a total water supply amount setting device; and the temperature deviation (TER). a water flow controller that outputs a signal for controlling the water supply amount in dependence on the signal from the water heater and the signal from the water heater; A water heater control device consisting of a water flow control device.