JPH0245781B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides an instantaneous water heater in which a sequence necessary for igniting a burner starts when a water flow generated by opening a hot water faucet is detected, and the water flow at the time of startup is appropriately controlled. This invention relates to a water flow regulator that is provided to adjust the water flow to a certain value.

Instant water heaters that start by detecting water flow take a long time to reach the set temperature, and water below the set temperature is often discarded, which defeats the purpose of saving water. .

This invention eliminates the above-mentioned conventional drawbacks,
An instant hot water system that can raise the temperature to a predetermined set temperature in a short time by restricting the amount of water supplied to the hot water tap when it detects that water is flowing when the hot water tap is opened. The purpose is to provide a water flow regulator for boilers.

By limiting the amount of water immediately after starting the instantaneous water heater to a value as low as possible within a range higher than the water amount detection limit, it is possible to raise the hot water temperature to the set temperature in a short time, and because it is below the set temperature. water that would have otherwise been wasted can be saved. The water volume restriction operation is canceled when one of the following conditions is met.

(1) When it is detected that a certain amount of time has passed since the water flow sensor detected water flow.

(2) When the water flow sensor detects water flow and then integrates the amount of water, and it is detected that this integrated value has reached a certain value.

(3) When the hot water temperature sensor detects that the hot water temperature has reached a certain level.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, numeral 1 is a burner;
2 denotes a heat exchanger heated by this burner 1, respectively. The burner 1 is supplied with gas through a pipe 4 having a gas valve 3 . Further, water is supplied to the heat exchanger 2 through a pipe 8 provided with a water flow control valve 5, a water governor 6, and a water flow sensor 7, and water heated in the heat exchanger 2 is taken out via a hot water tap 9. It's getting old. Water volume adjustment circuit 1
0 constitutes a water flow regulator together with a water flow control valve 5 and a water flow sensor 7.

This instant water heater performs the operations necessary for scavenging, igniting the pilot flame, and igniting the burner 1 according to a preset sequence when the water flow generated by opening the hot water tap 9 is detected. It has a function to automatically stop combustion when the hot water tap 9 is closed. The structure and operation for obtaining this function are well known in this field, so a detailed explanation thereof will be omitted. and flow rate adjustment circuit 10
limits the flow rate of water flowing out from the hot water faucet 9 to a predetermined value from the time when the water flow sensor 7 detects a predetermined amount of water flow until the water flow restriction operation condition described above is satisfied.

An example of the water amount adjustment circuit 10 is shown in FIG. When the operation switch SW is pressed, the operation lamp L lights up, the transistor Q1 becomes conductive, and its output is supplied to the microcomputer 11.
In addition, the output of the hot water temperature sensor 12 that detects the temperature of hot water taken out from the heat exchanger 2 (hot water temperature) is as follows:
After being converted into a digital signal by the A/D converter 13, it is input to the microcomputer 11. Furthermore, a water flow signal obtained from the water flow sensor 7 is also input to the microcomputer 11. The microcomputer 11 performs predetermined calculations based on these inputs and outputs the closing direction drive signal S1 or the opening direction drive signal S2. These signals S1 and S2 are passed through inverters 14 and 15, respectively, to transistors Q2 to Q5, diodes D1,
D2 and a servo amplifier consisting of resistors R1 to R4, which is used to control the servo motor 16. This servo motor 16 is connected to the water flow control valve 5.
This is for driving the door in the closing direction or opening direction. In addition, water flow control valve 5 is activated according to signals S1 and S2.
As a means for opening and closing, other pulp driving means other than a servo motor may be used.

FIG. 3 shows a timing chart of the operation of the water amount adjustment circuit 10 shown in FIG. 2. driving switch
When a water flow is detected after the SW is turned on, a closing direction drive signal S1 is supplied from the microcomputer 11 to the servo amplifier for a preset time t1, and the water volume control valve 5 performs an operation to throttle the water volume. As shown in FIG. 4, this water amount limiting operation is performed when the water amount reaches detection level 2, which is lower than fully open level 1, and thereby the water amount is reduced to level 3. At this point, the closing direction drive signal S1 disappears, and after the elapse of time t2 until the above-mentioned water amount restriction condition is released, the opening direction drive signal S2 is supplied to the servo amplifier for a predetermined time t3. With this, the water volume limiting operation is completed and the water volume is fully open level 1.
From this point on, steady operation begins. FIG. 5 shows a flowchart when the water amount restriction operation is canceled when a timer detects that a certain period of time has elapsed.

As a result of the water volume limiting operation as described above, the time from when the tap is opened until the desired hot water temperature is reached is significantly shortened, as shown in FIG. 6, compared to the conventional case where water volume is not restricted. Furthermore, the present invention improves the safety of the hot water temperature when the hot water tap is opened again within a short time after the hot water tap is closed. In other words, as shown in Figure 7, the general characteristic of instantaneous water heaters is that the temperature rises due to the so-called after-heating phenomenon immediately after the hot water tap is closed, and if operation is resumed during this period, the water volume will decrease. If water is not restricted, the hot water temperature will be extremely low and it will take time to reach the set temperature, but if water volume is restricted, the temperature will not drop as much after restarting operation, and the temperature will reach the set temperature. The time is short.

In this embodiment, a water flow sensor that generates a pulse signal with a frequency proportional to the amount of water is used to detect whether a water flow is generated by opening the hot water tap. Detection of the presence or absence of water flow is performed based on whether the frequency of this pulse signal exceeds a set value. The frequency can be measured by various known means, but for example, the level of the pulse signal is checked at a cycle shorter than the cycle corresponding to the highest frequency that can be output by the water flow sensor, and the interval of this level switching is It is possible to advantageously apply means for determining that a water flow has occurred when the length becomes shorter than a certain value. Of course, a water flow switch that operates when the amount of water exceeds a certain value can also be used.

As described above, the water flow rate regulator of the present invention controls the flow rate of water taken out from the hot water faucet from the time when the instantaneous water heater starts operating until the predetermined restriction condition is lifted.
Since the flow rate is limited to a value close to the minimum flow rate required for operation of the instantaneous water heater, the temperature of the hot water quickly rises to the desired set temperature. In addition, since the amount of water that flows out before the set temperature is reached is small, in addition to energy saving effects, water saving effects can also be obtained.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the configuration of an instantaneous water heater equipped with a water flow regulator according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a water flow control circuit used in the example of FIG. 1, and FIG. The figure is a timing chart of the circuit in Figure 2, Figure 4 is a graph showing the water flow rate adjustment pattern by the circuit in Figure 2, Figure 5 is a flow chart showing the operation of Figure 2, and Figures 6 and 7 are 2 is a graph showing changes in outlet temperature in the instantaneous water heater of FIG. 1 in comparison with a conventional case. 1...Burner, 2...Heat exchanger, 3...Gas valve, 5...Water flow control valve, 6...Water governor, 7...
...Water flow sensor, 9...Hot water tap, 10...Water flow control circuit, 11...Microcomputer, 12...
Outlet hot water temperature sensor, 13... A/D converter, 16...
…Servomotor.

Claims (1)

[Scope of Claims] 1. A water flow sensor that detects the water flow generated by opening the hot water tap of the instantaneous water heater, and a water flow control valve that adjusts the amount of water flowing through the heat exchanger of the instantaneous water heater; a water flow control circuit that controls the water flow control valve to limit the flow of water through the heat exchanger from the time when the water flow sensor detects a predetermined water flow until a preset water flow restriction condition is released; Water flow regulator for instantaneous water heaters equipped with 2. The water flow regulator in an instantaneous water heater according to claim 1, wherein the water flow restriction condition is canceled by a timer that operates after a certain period of time after the water flow sensor detects the water flow. 3. The above-mentioned water quantity restriction condition is canceled by a water quantity integrating means which integrates the water quantity after the water flow sensor detects the water flow and operates when this integrated value reaches a set value. A water flow regulator in the instantaneous water heater according to item 1. 4. The water amount regulator in an instantaneous water heater according to claim 1, wherein the water amount restriction condition is canceled when the temperature of the hot water exiting the heat exchanger reaches a predetermined value.