JPS5974425A - Hot water supply control device - Google Patents

Abstract

PURPOSE:To prevent the temperature of hot water from changing suddenly at the time when the quantity of water changes suddenly and also to prevent the temperature of hot water from changing due to after-heating by a method wherein a water quantity adjust valve is provided in a bypass passage bypassing a water passage of a heat exchange and the temperature of the hot water is controlled by adjusting the quantity of water in the bypass passage temporarily. CONSTITUTION:In case where the quantity of water reduces suddenly, the quantity of feed water to the heat exchanger 13 and to the bypass passage 16 reduces so that the temperature of the hot water increases rapidly. This increase in the hot water temperature is detected by a mixed hot water temperature detector 18 and the signal from the detector 18 is subjected to a PID operation at a heating control section 28 so that the amount of heating by a heating device 25 is reduced rapidly by adjusting a heating control device 24. At the same time, the signal from a heated hot water detector 15 is operated at a water quantity control section 29 so as to operate a drive device 22, the quantity of the water in the bypass passage 16 is increased by increasing the opening degree of the water quantity adjust valve 11 to thereby prevent the temperature of the hot water from increasing suddenly in a mixing section 17.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a hot water supply control device for an instant hot water heater, which automatically controls the amount of heating and the amount of water to perform temperature control.

Conventional Structure and Problems It is already known that instantaneous water heaters adjust the heating input and also automatically adjust the amount of water.

Fig. 1 shows a conventional example, in which the hot water temperature is detected by sensor A, the control circuit B controls the gas ilS example'1 [C] and the water flow control valve, and the water is heated by burner E. The outlet temperature of heat exchanger F is set to jllll mark a1.

However, in the conventional example shown in FIG.
F, 1: There are some problems. In other words, in response to sudden changes in water temperature that occur due to sudden changes in water volume, even if the combustion amount of burner E is adjusted or the age of heat exchanger F is adjusted, a time delay due to the heat capacity of heat exchanger F will occur. Therefore, it has little effect on sudden temperature changes. In particular, it is not effective for high-temperature hot water dispensing (post-boiling) when hot water is reheated after hot water has been supplied, and is not only uncomfortable for the user, but also poses a risk of burns.

Purpose of the Invention The present invention eliminates such drawbacks and improves the hot water temperature controllability of a water heater, and in particular, controls the outlet temperature to be equal to the set temperature even in response to sudden changes in hot water temperature due to sudden changes in water supply or post-boiling. The purpose is to

Structure of the Invention In order to achieve this object, the present invention provides a water flow control valve in the bypass passage that bypasses the heat exchanger passage, and adjusts the temperature of the mixed hot water at the outlet of the heat exchanger and the water in the bypass passage to the mixed water. The mixed water temperature is detected by a temperature detector, and the signal from this mixed water temperature detector and the hot water outlet temperature setting is compared to adjust the heating amount of the heating device, and the water flow rate control valve adjusts the amount of bypass water to control the hot water outlet temperature. This configuration prevents sudden temperature changes and provides stable hot water temperature.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In FIG. 2, reference numeral 1 denotes a water flow controller, in which water enters a valve chamber 3 from an inflow path 2, passes through a gap between a control valve 4 and a control hole 5, and flows into a primary chamber 6. Reference numeral 7 denotes a diaphragm that operates together with the control valve 4, and the other side forms a secondary chamber 8, and the secondary chamber 8 has a control spring 9 that biases it toward the secondary chamber 6 side. −
The water flowing into the next chamber 6 is connected to a venturi pipe 10 and a water flow control valve 1.
1, and the pressure in the low pressure part of the Venturi tube 10 is guided to the communication hole 12 and communicated with the secondary chamber 82. venturi tube 10
The water that has passed through is heated by a heat exchanger 13 and supplied to a hot water outlet pipe 14, and the temperature of the hot water is detected by a heated water temperature detector 16. Bypass path 16 from the hot water outlet pipe 14 and the control valve 11
The water and water are combined in a mixing section 17, and the temperature of the mixed water is detected by a mixed water temperature detector 18. The water volume adjustment valve 11 has a valve hole 19 and is driven by a drive device 22 consisting of a gear 2o and a motor 21 to adjust the water volume in the bypass passage 16. On the other hand, the gas passes through the heating controller 24 from the gas supply path 23 and is burned in the heating device 25 to heat the heat exchanger 13. 26 is a hot water supply controller which receives signals from the mixed water temperature detector 17 and heated water temperature detector 15, calculates them, and outputs them to the drive device 22 and the heating controller 24.

FIG. 3 shows a control block diagram of an embodiment of the present invention, in which the same members as in FIG. 2 are given the same numbers.

The hot water supply controller 26 includes a hot water temperature setting section 27 and a heating control section 28.
The water amount control section 29 includes a hot water temperature change rate calculation section 29a and a t-drive control section 29b. The hot water temperature is controlled by a hot water temperature setting section 27 consisting of a variable resistor and a mixed hot water temperature detector 18.
The respective signals are calculated by the heating control unit 27, and the deviation signals drive the heating controller 24 by known PID control, and the mixed water temperature is kept constant by adjusting the heating amount of the heating device 24. Water flow control is performed by calculating the rate of change of the deviation signal of the outlet hot water temperature setting unit 27 and the mixed hot water temperature detector 18 in the hot water temperature change rate calculating unit 29a, and driving according to the magnitude of the deviation signal and the magnitude of the rate of change of the deviation signal. A signal is sent to the control section 29b to drive the drive device 22.

Next, the operation will be explained. When the water flow starts in FIG.
The water flows into the bypass passage 16 from the water, and then merges again at the mixing section 1.

The water flow control valve 11 can be maintained at an appropriate opening degree set from the outside. As the water flows, a flow switch (not shown) is activated, the heating device 26 starts to burn, and the temperature of the water increases. Hot water heated by the heating device 25 and the bypass path 1
The unheated water of 6 is mixed in the mixing section 17, and the temperature of the mixed water is detected by the mixed water temperature detector 18. The deviation of the hot water temperature in line with the hot water temperature setting is determined by the hot water temperature setting section 26 in Fig. 3.
and the signal of the mixed water temperature sensor 18.
1 (calculated. After calculating in the heating control unit 28 based on this deviation signal, the heating controller 24 is driven by 1, and the heating device I":'
: Adjust the heating amount of 25 and control the hot water temperature. In this way, the hot water temperature d becomes equal to the set temperature. Consider a case where the amount of water suddenly changes due to the user operating the faucet or suddenly changing the water pressure.
: Since the water flow to the bypass road 16 is reduced, ri, 'r
The temperature rises rapidly by -1. This hot water temperature upper row is detected by the mixing temperature control detector 18, and the heating controller 28 performs PIDj and bowing to adjust the heating controller 24 to rapidly reduce the heating amount of the heating device 25. At the same time, j) [1) Calculate the reliability of the hot water temperature detector 15 using the water flow control unit 29, and
2 is activated to increase the opening degree of the water volume control valve 11 to increase the water volume in the bypass passage 16, thereby preventing the hot water temperature from rising rapidly in the mixing section 17. In the water flow control unit 29, the rate of change of the signal from the heated water temperature detector 15 is calculated by the hot water temperature change rate calculation unit 29a, and the magnitude of the change rate is calculated by the drive control unit 29b.
The amount of operation of the drive device 22 is determined. As described above, the water flow control valve 11 is adjusted according to the degree of change in the water temperature. It is highly effective to drive the water flow control valve 11 by changing the rotational speed of the motor 2o depending on the rate of change of the signal from the hot water temperature detector 15.

The water flow control valve 11, whose opening degree has been adjusted in this way to prevent transient changes in hot water temperature, returns to the opening degree before adjustment after the water temperature has stabilized. There are the following methods for returning.

(1) After a predetermined period of time, the opening returns to the original opening.

(Iku Heating Bottle Inspection 1) 4 When the direction of the change rate of the signal of device 15 is reversed, the opening returns to the pre-adjustment position.

The rotational speed of the motor 20 when the water volume control valve 11 returns can be driven at a low speed that does not interfere with transient water temperature changes.

PID control of the heating control section 28 and calculation of the water amount control section 29 can be easily performed by a microcomputer program.

Effects of the Invention The present invention provides a water spray control valve in a bypass passage that bypasses a heat exchanger water passage, and detects the temperature of the mixed hot water of the hot water at the outlet of the heat exchanger and the water in the bypass passage with a mixed hot water temperature detector. The heating amount of the heating device is adjusted based on the deviation signal between the mixed water temperature sensor and the outlet temperature setting, and the water temperature at the outlet of the heat exchanger is detected by the heated water temperature sensor. The signal drives the water flow control valve and temporarily adjusts the bypass water volume to control the hot water temperature, which prevents sudden changes in water temperature that occur when water volume suddenly changes, and also prevents changes in water temperature due to post-boiling. Since this can be prevented, the temperature of the hot water is stable, comfortable, and highly safe. In addition, the temperature of the hot water at the outlet of the heat exchanger is detected and mixed with water downstream of the heat exchanger, so the hot water temperature can be controlled without any time delay.Furthermore, a water flow control valve is installed in the passage that bypasses the heat exchanger. Because of this, during normal use,
It has the advantage of being able to obtain a large amount of hot water without increasing the pressure loss of the heat exchanger.

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[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional example of a hot water supply control device, FIG. 2 is a block diagram of an embodiment of the hot water supply control device of the present invention, and FIG. 3 is a control block diagram thereof. 11...Water flow control valve 1, 13...Heat exchanger, 15...Heating water temperature detector, 16...
...Bypass path, 17...Mixing section, 18...
... Mixed hot water temperature detector, 22 ... Drive device, 2
5...Heating device, 26...Hot water supply controller, 27...Hot water temperature setting section, 28...Mark/Heating control section, 29...Water amount control section.

Claims (1)

[Scope of Claims] (1) A heating device, a heat exchanger heated by the heating device, a bypass path that bypasses the water passage to the heat exchanger, and an outlet of the heat exchanger and the bypass path. a mixing water temperature detector provided downstream of the mixing section; a heated water temperature detector provided at the outlet of the heat exchanger; a water flow control valve provided in the bypass passage; and a driving device for the water flow control valve. and a hot water supply controller consisting of a hot water outlet temperature setting section, a heating control section, and a water amount control section, which adjusts the heating amount of the heating device based on the deviation signal of the mixed hot water temperature detector and the hot water outlet temperature setting section, and A hot water supply control device that temporarily adjusts the opening degree of the water flow control valve based on a signal from a hot water temperature detector. The hot water supply control device according to claim 1, which adjusts the opening degree of the water flow control valve according to the rate of change of the signal of the heated water temperature detector, and returns to the opening degree of the control valve after a predetermined time. The opening degree of the Wednesday control valve is adjusted according to the rate of change of a signal from a heated water temperature detector, and when the direction of the rate of change of the signal is reversed, the water flow rate control valve is returned to the opening degree before adjustment. The hot water supply control device according to claim 1. (4) The hot water supply control device according to claim 1, which changes the water flow rate adjustment speed according to the rate of change of the signal of the heated water temperature detector. The hot water supply control device according to claim 1, wherein the speed of returning to the opening degree is lower than the adjustment speed.