JPS60259854A - Control device for hot water supply - Google Patents

Abstract

PURPOSE:To reduce the pressure loss in feed water circuit and at the same time contrive to stabilize the temperature of hot water delivery by a method wherein a single drive gear controls both the total amount of feed water and the amount of water bypassing a heat exchanger and at the same time is driven in association with the setting of the temperature of hot water delivery. CONSTITUTION:A heat exchanger 8 heated by a heating device 28 and a passage 11 bypassing the heat exchanger 8 are provided. A water flow detector 3 to detect the amount of feed water, a water flow controller 1, which consists of a main control valve 5 to control the amount of feed water and a bypass control valve 9 provided in the bypass passage, and the drive gear 17 of the water flow controller are equipped. The drive gear 17 is operated by the signal sent from the water flow detector 3 so as to control the amount of feed water and at the same time to adjust the opening of the bypass control valve 9. And yet, a heating controller 27 is controlled by the deviation signal between the signals from a delivery hot water temperature setter 30 and from a hot water delivery temperature detector 14. At the same time, the maximum manipulated variable of the drive gear or the maximum opening of the bypass control valve 9 is regulated in response to the signal from the hot water delivery temperature setter 30.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to the control of water flow rate in household instant hot water heaters. Are known.

Further, as a known technique, there is a bypass water circuit system in which a bypass path is provided to bypass a heat exchanger in order to reduce the pressure loss of flowing water, and the water is mixed with hot water heated by the heat exchanger and then supplied. When the hot water outlet temperature control and water supply amount control are combined with the bypass water circuit method, (1) boiling occurs in the heat exchanger when the hot water outlet temperature setting is high and the ratio of the bypass water amount is large.

(2) The effect of reducing pressure loss is small unless the amount of bypass water is increased.

(3) Two drive 3-base devices are required for water supply control and bypass control.

There were drawbacks such as.

Purpose of the Invention The present invention controls the total amount of water supplied to a hot water supply system and the amount of bypass water of a heat exchanger with one drive device, and drives the drive device in conjunction with the setting of the hot water temperature. The purpose is not only to reduce pressure loss in the circuit, but also to stabilize the hot water temperature.

Structure of the Invention In order to achieve this object, the present invention includes a heat exchanger heated by a heating device, a bypass path that goes around the heat exchanger, a water amount detector that detects the amount of water supplied, and a water amount detector that detects the amount of water supplied. It has a water flow controller consisting of a main control valve to control and a bypass control valve installed in a bypass path, and a drive device for this water flow controller, and the drive device is operated by a signal from the water flow detector to control the water supply amount. and adjust the opening degree of the bypass control valve,
In addition, the maximum operating amount of the drive mounting, that is, the maximum opening degree of the bypass control valve, is regulated in accordance with the signal from the outlet hot water temperature setting device.

DESCRIPTION OF EMBODIMENTS An embodiment in which the present invention is applied to a gas instantaneous water heater will be described. In Fig. 1, 1 is a water flow controller, in which water flows in from an inlet channel 2, passes through a water flow detector a, enters an inlet valve chamber 4, passes through a gap between a main control valve 5 and a main control hole 6, and exits through a gap between a main control valve 5 and a main control hole 6. It flows into the valve chamber 7. The water flow is divided into two directions from the outlet valve chamber 7,
One flows to the heat exchanger 8 , and the other flows to the bypass path 11 through the gap between the bypass control valve 9 and the bypass control hole 10 , and joins the outlet pipe 12 of the heat exchanger 8 . The mixing section 13 has a hot water temperature detector 14 . The water amount detector 3 includes an impeller 15 whose rotation speed changes in proportion to the speed of water flow, and a rotation detection element 16 which detects the rotation speed of the impeller 15. 17 is a drive device including a morph 18, a decelerator 19,
Consists of valve position detector 20, link machine front 21, valve stem 22
The bypass control valve 9 and the main control valve 5 are respectively operated through the control valve 9 and the main control valve 5. The valve stem 22 slides in the inner hole of the bypass control valve 9, but when the locking ring 23 fixed to the valve stem 22 comes into contact with the bypass control valve 9, the return spring 24 causes the valve valve 22 and the bypass control valve 9 to be separated. moves as one.

Similarly, the return spring 25 constantly displaces the main control valve 5 in accordance with the movement of the valve stem 22. As is clear from the figure, the bypass control valve 9 is arranged so as to open after the main control valve 5 opens at a predetermined angle.

The gas is supplied from the gas supply path 26 to the heating device 28 with the gas amount adjusted by the heating controller 27, where it is combusted and heats the heat exchanger 8. 29 is an inlet water temperature detector such as a thermistor, and 30 is an outlet water temperature setting device composed of a variable resistor or the like. 31 is a hot water supply controller consisting of a microprocessor, etc., which inputs signals from a water flow rate detector 3, a hot water outlet temperature detector 14, an incoming water temperature detector 29, and a hot water outlet temperature setting device 30, and sends the signals to a drive device 17 and a heating controller 27. Output a signal.

Next, an overview of the operation will be explained. In FIG. 1, when the power is turned on and water flow starts, a signal from the water amount detector 3 is read, fuel is supplied to the heating device 28, and combustion starts. And heat exchanger 8 nM + -) r size apricot nail μ Vanopas catfish 11 is put into the pump. Heating controller 2 by deviation
7 is driven to control the heating amount of the heating device 28. Further, the amount of water supplied is controlled by driving a drive device 17 based on a signal from the water amount detector 3.

Next, the control operation will be explained in more detail with reference to FIG.

When the power is turned on and the hot water temperature is set by the user, the signal from the hot water temperature setting device 30 is read into the hot water supply controller 31, and the drive limiter 31a inside the hot water supply controller 31 is read.
The maximum drive amount of the drive device 17, that is, the maximum opening degree of the bypass control valve 9, is calculated according to the hot water temperature setting. In addition, the water amount setting calculation unit 31b of the hot water supply controller 31 detects the signal difference between the hot water temperature setting device 30 and the incoming water temperature detector 29,
A calculation is performed with the preset heating capacity of the heating device 28 to set the maximum amount of water at which the hot water temperature set by the hot water temperature setting device 30 is guaranteed. After that, when the water flow is started, the water amount detector 3 detects the amount of water supplied, and when it reaches the amount of water supplied (ignition start water amount) or more, fuel is supplied to the heating device 28 and the ignition operation is performed to start the combustion of the heating device 28. starts. The amount of water at which the ignition starts can be changed by a preset constant value or by a signal from the hot water temperature setting device 30. The main control valve 5 controls the total amount of water supplied before being divided into the heat exchanger 8 and the bypass path 11, and the bypass control valve 9 controls the ratio of water distribution between the heat exchanger 8 and the bypass path 11. 1st
In the figure, the bypass control valve 9 is in a fully closed state, and all water flows to the heat exchanger 8. In this state, if the water supply amount is larger than the value set by the water amount setting calculation unit 31b, the driving device 17 is driven to move the main control valve 5 in the closing direction to reduce the water supply amount. Conversely, if the water supply amount is smaller than the set value, the main control valve 5 is opened to increase the water supply amount, but if the water supply pressure is low and the water supply amount is not sufficient, the drive device 17 is further driven to close the locking ring 23. contacts the bypass control valve 9, and the main control valve 5
While opening, the bypass control valve 9 is moved in the opening direction to start water flow to the bypass path 11 side. Therefore, by supplying water to the bypass passage 11 that bypasses the heat exchanger 8 which has a high pressure loss, a large amount of water can be secured even at low water pressure.

The heating amount of the heating device 28 is adjusted by the heating controller 27. The heating controller 27 is controlled by the heating load value calculated by the hot water temperature control calculation unit 31d based on the signal difference between the output water temperature setting device 30 and the incoming water temperature detector 29, and the signal from the water amount detector 3. Further, correction is made using a deviation signal between the hot water outlet temperature setting device 30 and the hot water outlet temperature detector 14, and finally a hot water outlet temperature equal to the hot water outlet temperature setting value is obtained.

FIG. 3 shows the signal from the valve position detector 20, that is, the relationship between the valve position and the bypass water amount ratio to the total water supply amount, based on the fully closed position of the main control valve 5. Main control valve 5
After opening by a predetermined amount, the bypass control valve 9 begins to open. The drive limiter 31a prevents the boiling phenomenon that occurs when the tapped water temperature setting value is high and the ratio of the amount of water on the bypass path 11 side is higher than that on the heat exchanger 8. That is, the drive IJ limiter 31a regulates the maximum opening degree of the bypass control valve 9, and its value is calculated based on the signal of the outlet hot water temperature setting value 30. Drive IJ Mick 3
1a allows the opening degree of the bypass control valve 9 to be relatively large when the set value of the hot water outlet temperature is low, and on the contrary, regulates the opening degree of the bypass control valve 9 to be relatively small when the set value of the hot water outlet temperature is high. The value of the drive limiter 31a is determined by the valve position detector 2.
0 signal, the maximum value of the drive of the drive device 17 is regulated, and the maximum opening degree of the bypass control valve 9 is limited in advance to maintain an appropriate water flow ratio on the bypass path 11 side.

The valve drive control mechanism is a servo machine groove, and the position of the main control valve 5 is detected by a valve position detector 20 and fed back. A position sensing switch is used to allow open loop control.

Next, consider a case where the water volume suddenly changes. The amount of water supplied may change suddenly due to the user suddenly opening and closing the faucet or sudden changes in the water supply pressure. When the water volume suddenly changes, the heat exchanger 8's heat capacity causes high temperature hot water to be generated when the water volume suddenly changes, and low temperature hot water to be generated transiently when the water volume suddenly increases. The water amount control mechanism of the present invention thus has a function of alleviating transient fluctuations in wetness caused by sudden changes in water amount. That is, when the amount of water suddenly decreases, the amount of water is detected by the water amount detector 3, and the drive device 17 is operated to open the main control valve 5 to adjust the amount of water supplied. At this time, the bypass control valve 9 also moves in the opening direction at the same time, so the ratio of the amount of bypass water increases, and the high temperature hot water generated in the heat exchanger 8 is diluted. On the other hand, when the amount of water increases rapidly, the ratio of bypass water amount decreases to compensate for the low temperature of hot water and provide a comfortable hot water temperature.

As described in "Effects of the Invention", the present invention drives the heating controller based on the deviation between the hot water temperature setting device and the hot water temperature detector, controls the heating amount of the heating device, heats the heat exchanger, and adjusts the amount of water supplied. The main control valve that controls the heat exchanger, the bypass control valve installed in the bypass path of the heat exchanger, and the wastewater flow rate controller are all driven by one drive device. (2) Fluctuations in hot water temperature at the outlet of the heat exchanger due to sudden fluctuations in water volume can be corrected by changing the bypass ratio, and transient fluctuations in hot water temperature can be reduced.

It has this effect.

In addition, since the maximum operation amount of the water flow rate controller drive device is regulated by the signal from the hot water outlet temperature setting device, (3) when the hot water outlet temperature is set high, the bypass water volume ratio is kept small and boiling in the heat exchanger is prevented. (4) When the hot water temperature is set low, the bypass water flow rate increases, and a large amount of hot water can be discharged even with low water pressure.

It has this effect.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a hot water supply control device showing one embodiment of the present invention, FIG. 2 is a block diagram showing control signals of the same device, and FIG.
The figure is a characteristic diagram showing the relationship between the bypass water amount ratio and the valve displacement amount of the device. 1...Water flow controller, 3...Water flow detector, 5...
- Main control valve, 8... Heat exchanger, 9... Bypass control valve, 11... Bypass path, 14... Hot water temperature detector, 17... Drive device, 20... ... Position detector, 27 ... Heating controller, 28 ... Heating device, 30 ... Hot water temperature setting device, 31 ... Hot water supply controller.

Claims (3)

[Claims] (1) A heat exchanger, a heating device for the heat exchanger, a heating controller that controls the heating amount of the heating device, a bypass path that bypasses the heat exchanger, and a water amount detector that detects the amount of water supplied. a water flow controller consisting of a main control valve that controls the water supply flow and a bypass control valve provided in the bypass passage; a drive device for the water flow controller; deviations between the hot water temperature setting device and the hot water temperature detector; and a hot water supply controller that controls the heating controller with a signal and also controls the water flow controller with a signal of the water flow detector, and the maximum operation amount of the drive device is regulated by the signal of the hot water temperature setting device. Hot water control device. (2) The hot water supply control device according to claim 1, wherein the bypass control valve starts opening after the main control valve has been opened for a predetermined amount of time. (3) The hot water supply control device according to claim 1, wherein the water flow controller or the drive device includes a position detector for detecting the position of the main control valve or the bypass control valve.