JPH06202741A - Method for controlling temperature of discharged hot water in hot water storage type hot water supplier - Google Patents

Abstract

PURPOSE:To provide the method for controlling the temperature of discharged hot water in a hot water storage type hot water supplier which prevents an undershoot phenomenon at the time of discharging hot water again after temporary stop and prevents discharge of hot water at a high temperature due to a fault of a water quantity sensor or the like. CONSTITUTION:A water supply pipe 6 of a heat exchanger used as a hot water storage tank connecting this pipe 6 and a hot water supply pipe 7 is provided with a water quantity sensor 9, and a flow rate control valve 11 is provided on the way of a bypass pipe 8 which is branched from below the sensor 9 and is connected to the hot water pipe 7, and the hot water supply pipe 7 is provided with a water and hot water mixture temperature sensor 13 below the connection part to the bypass part 8, and hot water discharge at a set temperature is controlled based on detection signals of sensors 9 and 13. When hot water is discharged again after temporary turning-off of a water cock metal fitting 12 attached to the front end of the hot water supply pipe 7, a set temperature change signal during this turning-off is detected, and the flow rate control valve 11 is immediately operated in the opening direction to control the temperature of hot water to be discharged in spite of the detecting signal of sensor 9 if the changed set temperature is lower than the set temperature just before this temporary turning-off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage hot water dispenser capable of preventing undershoot phenomenon when hot water is once stopped and then hot water is discharged again, and hot water from being discharged due to a failure of a water amount sensor or the like. The present invention relates to a temperature control method.

[0002]

2. Description of the Related Art Conventionally, a hot water storage type water heater B as shown in FIG.
There is a water quantity sensor in the middle of the water supply pipe 52 to the heat exchanger 51 also serving as a hot water storage tank, which includes the water supply pipe 52 and the hot water supply pipe 53.
54 provided, in the middle of the bypass pipe 55 branched from the downstream side of the water amount sensor 54 and connected to the middle of the hot water supply pipe 53, the amount of water passing through the bypass pipe 55 based on the detection signal of the water amount sensor 54. A flow rate control valve 56 for adjusting is provided, and further,
A mixed hot water temperature sensor 57 is provided in the hot water supply pipe 53 which is located downstream of the connection between the hot water supply pipe 53 and the bypass pipe 55.

Then, the respective sensors 54, 57 and the flow rate control valve 56 are connected to a control section 58 provided on the water heater B side, and based on the detection signals of the water amount sensor 54 and the mixed hot water temperature sensor 57, By adjusting the opening and closing angle of the flow control valve 56,
Feedback control is performed to keep the hot water temperature at the set temperature.

In FIG. 5, 59 is a controller that can be operated remotely, 60 is a water faucet metal fitting, and 61 is a motor for the flow control valve 56.

[0005]

However, the above-mentioned hot water storage type water heater B still has the following problems to be solved.

That is, after tapping hot water at a set temperature, once closing the faucet metal fitting 60 such as a calan and reopening it,
In the case of so-called hot water discharge after one stop, as shown in Fig. 5, hot water higher than the set temperature flows out first (overshoot), and hot water lower than the set temperature flows out subsequently (undershoot). Was occurring.

This is because after one stop, the temperature around the mixed hot water temperature sensor 57 is warmed by heat conduction from the heat exchanger 51 also serving as a hot water storage tank, so that the mixed hot water temperature sensor 57 has a high temperature even though there is no water. Since the control unit 58 operates the flow rate control valve 56 in the opening direction based on the detected value, the faucet fitting 60
When is opened, warm water near the mixed hot water temperature sensor 57 will come out, and after that, hot water diluted with water due to the operation of the flow rate control valve 56 will come out below the set temperature. is there.

[0008] In particular, the undershoot from which hot water below the preset temperature flows out gives the user an unpleasant feeling, and improvement thereof has been desired.

Further, after one stop, for example, when the set temperature is changed from the high temperature side to the low temperature side to try to discharge hot water, the water amount sensor 54 normally detects the opening of the faucet metal fitting 60,
The control unit 58 tries to actuate the flow rate control valve 56 in the opening direction based on the detection signal, but if the water amount sensor 54 fails, the flow rate control valve 56 is opened when the faucet metal fitting 60 is opened. Hot water will come out without operating.

Therefore, there is a danger that a user who does not think that hot water will come out will get burned, which is very dangerous.

An object of the present invention is to provide a hot water outlet temperature control method in a hot water storage type water heater capable of solving the above problems.

[0012]

According to the present invention, a water quantity sensor is provided in the water supply path of a heat exchanger that also serves as a hot water storage tank for connecting the water supply path and the hot water supply path, and the hot water supply path is branched from the downstream side of the water quantity sensor. A flow rate control valve for adjusting the amount of water passing through the bypass passage is installed in the middle of the bypass passage connected to the hot water supply passage, and a mixed hot water temperature sensor is provided in the hot water supply passage downstream of the connection between the hot water supply passage and the bypass passage In a hot water storage type water heater configured to control hot water discharge at a set temperature based on detection signals of a water amount sensor and a mixed hot water temperature sensor, when hot water is to be tapped again after temporarily closing the faucet metal fitting attached to the tip of the hot water supply passage,
When the set temperature change signal is detected while the faucet metal fitting is closed and the changed set temperature is lower than the set temperature immediately before the faucet metal fitting was temporarily closed, regardless of the detection signal of the water volume sensor, The present invention provides a method for controlling the outlet hot water temperature in a hot water storage type hot water supply device, which is characterized in that the flow control valve is immediately operated in the valve opening direction to control the outlet hot water temperature.

Further, according to the present invention, when the set temperature change signal is not detected, the flow rate control valve based on the detected value of the mixed hot water temperature sensor is not operated until a fixed time elapses from the start of the re-melting hot water, and the constant value is maintained. It is also characterized in that the outlet heated water temperature is controlled based on the detection value of the same mixed hot water temperature sensor after the passage of time.

[0014]

Embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a schematic explanatory view of a hot water storage type water heater A according to the hot water temperature control method according to the present invention, and FIG. 2 is a flowchart showing the control method.

The hot water storage type hot water supply apparatus A in this embodiment is housed in a casing 1. The casing 1 has a heat exchanger 2 serving also as a hot water storage tank at its upper part and a combustion burner 3 at its lower part. It is provided.

The heat exchanger 2 also serving as a hot water storage tank is constructed by penetrating a large number of vertical smoke outflow tubes 2b through the tank body 2a.

A temperature sensor 4 such as a thermistor is provided in the tank main body 2a of the heat exchanger 2 that also serves as a hot water storage tank, and the temperature sensor 4 detects the hot water temperature in the tank main body 2a to distribute the temperature inside the casing 1. The combustion burner 3 is ignited and extinguished through the control unit 5 provided, and the hot water temperature in the hot water storage tank / heat exchanger 2 is controlled within the set temperature.

A water supply pipe 6 and a hot water supply pipe 7 serving as a water supply passage and a hot water supply passage are connected to the tank body 2a, and a bypass pipe 8 is interposed between the water supply pipe 6 and the hot water supply pipe 7. I have set up.

The water supply pipe 6 has a base end connected to a water source (not shown) and a terminal end connected to an inflow port 2c of the tank body 2a of the heat exchanger 2 also serving as a hot water storage tank. A pressure reducing valve 10 and a water amount sensor 9 are incorporated.

The water amount sensor 9 detects the water supply amount and inputs it to the control unit 5. Based on the detection signal of the water amount sensor 9, the control unit 5 outputs an operation signal to a flow rate control valve 11 described later. . The pressure reducing valve 10 is for keeping the water pressure in the tank body 2a at a predetermined pressure.

On the other hand, the hot water supply pipe 7 has its base end connected to the outflow port 2d of the tank main body 2a, and has a faucet metal fitting 12 such as a calan attached to the end thereof. A sensor 13 is provided.

The bypass pipe 8 has a pressure reducing valve at one end.
A water supply pipe 6 which is on the downstream side of 10 is connected to be connected to one place, and the other end is connected to an upstream side of the mixed hot water temperature sensor 13 of the hot water supply pipe 7.

The flow control valve 11 driven by the electric motor 16 is mounted in the middle of the bypass pipe 8.

The opening of the flow rate control valve 11 is controlled by the control unit 5, so that a required amount of water from the water supply pipe 6 can flow into the hot water supply pipe 7 to produce a mixed hot water.

The temperature of the mixed hot water discharged is detected by the mixed hot water temperature sensor 13 and the detection signal is fed back to the control unit 5, whereby the control unit 5 gives a signal indicating the opening degree of the valve of the flow rate adjusting valve 11. Is output so that the hot water mixed at the set temperature can be discharged.

Further, in FIG. 1, reference numeral 14 is a controller, which is mounted near the place where the faucet fitting 12 serving as a tap is provided, for example, in a kitchen, a washroom, a bathroom, or the like.

The controller 14 is connected to the control unit 5 and can perform all operations of the hot water storage type hot water supply device A such as operation start / stop and temperature setting.

The hot water storage type water heater A according to this embodiment is configured as described above, and the gist of the present invention is to provide the hot water heater A as described above.
In the case of temporarily closing the faucet metal fitting 12 attached to the tip of the hot water supply pipe 7 and tapping hot water again, a set temperature change signal is detected while the faucet metal fitting 12 is closed, and the changed set temperature is When the temperature is lower than the set temperature immediately before the plug fitting is temporarily closed, regardless of the detection signal of the water amount sensor 9, the flow control valve 11 is immediately activated to control the hot water temperature, and the set temperature change signal is not detected. In the case, the flow control valve 11 is not operated based on the detection value of the mixed hot water temperature sensor until a certain time has elapsed from the start of re-melting, and after a certain time,
It is to control the tapping temperature based on the value detected by the mixed hot water temperature sensor.

Here, the hot water storage type water heater A in this embodiment is used.
The gist of the present invention will be described in detail while describing the case of actually using.

First, when the operation start switch of the controller 14 is turned on, the flow rate control valve 11 once drives to the fully open position and then returns to the original position, and the control unit 5 causes the valve 11 to operate.
When the fully open position of is detected and it is confirmed that there is no abnormality in the operation of the valve 11, the operation start standby state is entered.

At this time, if the control unit 5 cannot detect the fully opened position of the flow rate control valve 11 within 20 seconds, it is determined that the flow rate control valve 11 has an error and the control unit 5 stops the valve 11 at that time. Then, an operation stop instruction signal is output, and an abnormality is displayed on the controller 14.

By such control, the hot water supply device A can be safely operated.

Next, when the temperature is set, the control section 5 drives the flow rate control valve 11 to a position having an opening corresponding to the set temperature.

The user can use the hot water having the set temperature, and can further change the set temperature while using the hot water. When there is a change, the changed set temperature and the mixed hot water temperature sensor 13 are compared, so that the control unit 5 immediately outputs a signal instructing the flow control valve 11 of the required drive amount.

By the way, when the user of the hot water closes the faucet metal fitting 12 to temporarily stop the hot water discharge, that is, when the hot water is stopped one time, the control when the hot water is again discharged is as described above. And will be described below with reference to FIG.

When hot water is to be discharged again after being stopped for one time, the control section 5 first judges whether or not the temperature setting is changed during the one stop (101) by a signal from the controller 14 (102).

When the temperature setting is changed (10
3) judges whether the changed set temperature is lower than the set temperature immediately before one stop (104).

When it is detected that the set temperature change signal is lower than the set temperature immediately before one stop (105), the control unit 5
Immediately outputs a drive signal to the flow control valve 11 to operate in the opening direction (106).

Further, when it is detected that the changed set temperature is higher than the set temperature immediately before the one stop (107), the control unit 5 inputs the detection value of the water amount sensor 9 (108), and the detection value is set to the detection value. Based on this, a drive signal is output to the flow control valve 11 (109) or a stop signal is output to the valve 11 (110).

That is, in the present embodiment, when the temperature setting is changed to a higher one (107), the water amount sensor 9 indicates that the water amount value (2 liters / min or more) at which the hot water storage water heater A can safely supply hot water. When detection continues for 3 seconds (108), a drive signal is output to drive the flow control valve 11 in the closing direction (109).
Drive 11 (111), and set temperature ± 1 ℃ as described later.
Control to keep between.

However, if the water amount sensor 9 detects a value below the above water amount value (2 liters / minute) even for a moment, the control unit 5 outputs a drive stop signal for the flow control valve 11.
(110) The same valve 11 is stopped (112), and further, a safety circuit works so that the set temperature also changes to a set temperature lower than the changed temperature one stop before.

When the temperature setting after the one stop is changed to a lower temperature (105), the control unit 5 immediately drives the flow rate control valve 11 in the opening direction (106) to increase the amount of water and the hot water. Control to lower the temperature. However, when the flow control valve 11 is in the fully open position, the valve 11 is stopped at that position.

Thereafter, it is judged whether or not there is a detection signal from the water amount sensor 9 (113), and when hot water is detected (114), the control section 5 compares the detected value from the mixed hot water temperature sensor 13 with the set temperature. Do (115). At this time, the control unit 5 maintains the opening of the flow rate control valve 11 within the set temperature ± 1 ° C while (116) adjusting the opening of the flow rate control valve 11 according to the detected value fed back. If it is determined that the flow rate is being maintained (117), the flow control valve 11 is stopped at that opening (118).

On the other hand, when the control unit 5 does not detect the signal from the water amount sensor 9 (119), that is, even when the hot water has not yet been tapped, the detected value from the mixed hot water temperature sensor 13 is compared with the set temperature. (120), and if the hot water temperature can be maintained within the set temperature ± 1 ° C (121), the same as above.
The flow control valve 11 is stopped (122) to prepare for tap water (123).

However, if the controller 5 judges that the hot water temperature cannot be maintained within the set temperature ± 1 ° C. (124), the controller 5 detects the fully open limit of the flow rate control valve 11 at this time. If it is detected (126), it is judged that further temperature adjustment is impossible, the flow control valve 11 is stopped at the current position (122), and the hot water is prepared in the same manner as above (123).

When the full open limit cannot be detected (127)
Means that routine a of FIG. 2 is repeated for a predetermined time,
Hot water is discharged during that time (113), and if the hot water temperature can be maintained at the set temperature ± 1 ° C, there is no problem, but no hot water is discharged (119),
Moreover, the set temperature range of ± 1 ° C cannot be maintained, and
When the fully open limit of the flow rate control valve 11 cannot be detected, the control unit 5 causes the same valve as the error at the initial stage of the operation described above.
11 is stopped at that point, an operation stop instruction signal is output, and an abnormality is displayed on the controller 14.

Further, when the routine a described above is present,
If the water amount sensor 9 detects a water amount value of 2 liters / minute or more even for a moment, the control unit 5 restarts the control so as to reach the set temperature, and the detected value of the water amount sensor 9 is 1.2 liters / min.
The flow control valve 11 is stopped at the time when the time becomes minute. The value detected by the water amount sensor 9 of 1.2 liters / minute is a safety allowable limit value corresponding to the capacity of the hot water storage water heater A.

Therefore, for example, if the set temperature is changed from 75 ° C. to 42 ° C. during one stop, the flow rate control valve 11 is immediately driven in the opening direction before the faucet fitting 12 is opened.
The hot water is safe because the amount of mixed water increases and the hot water at 75 ° C does not come out from the faucet metal fitting 12.

Further, when the faucet metal fitting 12 is opened, even if the control unit 5 cannot judge the opening of the water faucet metal fitting 12 due to a failure of the water quantity sensor 9 or the like, the flow rate control valve 11 is operated by It is also safe because it has already been driven in the opening direction before it is opened.

On the other hand, when the control unit 5 does not detect the change of the set temperature after one stop (128), the control unit 5 judges whether or not the water amount sensor 9 has detected the water amount (129), and the faucet fitting 12 Is opened and hot water is discharged, and when the water amount sensor 9 detects the water amount (130), whether or not a predetermined time has passed this time.
Judge (131).

Then, the flow control valve is operated until a predetermined time elapses.
When 11 is stopped (132) and the elapse of a predetermined time is detected (133), the control unit 5 responds to the change in the detection value of the mixed hot water temperature sensor 13 during that time (after 2 seconds have elapsed). The flow control valve 11 is operated to adjust it appropriately (134), and the control is performed to keep the set temperature within ± 1 ° C.
(135).

This is because when the flow rate control valve 11 is activated immediately after detecting the amount of water (detecting hot water), the vicinity of the mixed hot water temperature sensor 13 is warmed by heat conduction from the heat exchanger 2 during one stop. Therefore, the mixed hot water temperature sensor 13 detects the warmed hot water temperature, and the control unit 5 outputs a signal instructing the flow control valve 11 to open an opening more than necessary. As a result, a remarkable undershoot phenomenon occurs.

Therefore, if the set temperature is not changed during one-stop by performing the above control, FIG.
As shown in, the undershoot when the faucet fitting 12 is opened after one stop can be considerably improved.

When no change in the set temperature is detected (1
28), if the water quantity sensor 9 does not detect the water quantity (1
36) That is, if the hot water is not discharged, the control unit 5 stops the flow control valve 11 as it is (the state before the one stop) (137) to prepare for the hot water (138).

By performing the control as described above, the hot water storage type water heater A according to the present invention has an undershoot phenomenon or a high temperature when the set temperature is changed to a low value when the hot water is temporarily discharged and then hot water is discharged again. There is no such thing as leaving the bath.

In particular, when the temperature is greatly lowered from the state of use of the hot water, for example, even if the water amount sensor fails, the hot water before the setting change is not discharged as it is, so that the user is burned. It is very safe without fear of

In the above control, in this embodiment, the water amount sensor 9 is set to 2 when the set temperature is within the range of 38 ° C to 46 ° C.
If the mixed hot water temperature sensor 13 detects a hot water temperature of 56 ° C or higher while detecting a value of liters / minute or higher, an error is detected in the flow control valve 11 and the operation is stopped on the spot. There is. Further, the controller 14 is further enhanced in safety by displaying an abnormality.

In this embodiment, the one-can-one-circuit hot-water storage water heater A has been described. However, the present invention is not limited to this, and for example, a bath reheating function 1
It can also be applied to a two-circuit can hot water storage type water heater.

[0060]

According to the present invention, when the faucet fitting attached to the tip of the hot water supply passage is temporarily closed and then hot water is reapplied, the set temperature change signal is detected and changed while the faucet fitting is closed. When the set temperature is lower than the set temperature immediately before the faucet was closed temporarily, the hot water temperature was controlled by immediately operating the flow rate control valve in the opening direction regardless of the detection signal of the water amount sensor. It is extremely safe because the hot water temperature can be reliably lowered.

When the set temperature change signal is not detected, the flow rate control valve based on the detected value of the mixed hot water temperature sensor is not operated until a fixed time elapses from the start of re-hot water discharge,
Since the hot water outlet temperature is controlled based on the detection value of the same mixed hot water temperature sensor after a certain period of time, even if the vicinity of the mixed hot water temperature sensor is warmed by the conduction heat from the heat exchanger,
The temperature of the hot water after the hot water is discharged is detected to control the temperature, and the flow control valve is not opened unnecessarily, and the undershoot phenomenon at the time of re-hot water is suppressed as much as possible. Therefore, the user can comfortably use the hot water.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a hot water storage type water heater according to a control method of the present invention.

FIG. 2 is a flowchart showing control according to the present invention.

FIG. 3 is a graph showing a relationship between hot water temperature and time when hot water is tapped after temporarily closing the water faucet metal fitting.

FIG. 4 is an explanatory diagram of a hot water storage type water heater according to a conventional control method.

FIG. 5 is a graph showing a relationship between hot water temperature and time when hot water is discharged after temporarily closing the faucet metal fitting in the water heater.

[Explanation of symbols]

 2 Heat exchanger that also functions as a hot water storage tank 6 Water supply pipe 7 Hot water supply pipe 8 Bypass pipe 9 Water amount sensor 11 Flow rate control valve 12 Faucet fitting 13 Mixed hot water temperature sensor A Hot water storage water heater

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Soji Yano 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Nihon Yupro Co., Ltd. (72) Inventor Takayoshi Morioka 43, Uozaki-hama-cho, Higashinada-ku, Kobe No. 1 Nihon Yupro Co., Ltd. (72) Inventor Nobuhisa Sasaki 43-1 Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture Nihon Yupro Co., Ltd. (72) Inventor Shoji Inoue 2-chome, Nakajima, Kitakyushu, Fukuoka No. 1 No. 1 Totoki Equipment Co., Ltd.

Claims (2)

[Claims] 1. A water amount sensor is provided in a water supply passage of a heat exchanger that also serves as a hot water storage tank that connects the water supply passage and the hot water supply passage, and is provided in the middle of a bypass passage branched from the water quantity sensor and connected to the hot water supply passage. , A flow rate control valve for adjusting the amount of water passing through the bypass passage, and a mixed hot water temperature sensor in the hot water supply passage downstream of the connection between the hot water supply passage and the bypass passage. In a hot water storage water heater that is configured to control hot water discharge at a set temperature based on the detection signal of, when tap water is temporarily closed after tapping the water tap fitting attached to the end of the hot water supply passage, close the water tap fitting. When the set temperature change signal is detected during the operation, and the changed set temperature is lower than the set temperature immediately before the faucet was closed temporarily, the flow control valve is opened immediately regardless of the detection signal of the water volume sensor. Works on Hot water temperature control method in hot-water storage type water heater was and controlling the tapping temperature. 2. When the set temperature change signal is not detected, the flow rate control valve based on the detection value of the mixed hot water temperature sensor is not operated until a fixed time elapses from the start of re-hot water discharge,
The hot water temperature control method in a hot water storage type water heater according to claim 1, wherein the hot water temperature is controlled based on a value detected by the mixed hot water temperature sensor after a lapse of a certain time.