JPH0658626A - Restraining method for fluctuation of hot-water temperature - Google Patents

Abstract

PURPOSE:To supply hot-water while changing a hot-water/water mixing ratio, applied to a set hot-water temperature, in accordance with a water-stopping time and the temperature of cold water upon using continuously. CONSTITUTION:A time from putting OFF of a water flow switch to the putting ON is measured as a time of stopping water while generation of undershoot or overshoot is judged from the water stopping time. When the undershoot is generated, a hot-water outlet temperature is made higher than a set temperature by a predetermined value and, on the other hand, when the overshoot is generated, a procedure to reduce the hot-water outlet temperature than the set temperature by a predetermined value, is effected. Further, a time of supplying hot-water with a changed hot-water/water mixing ratio is regulated in accordance with the water stopping time and, thereafter, a procedure to discharge hot-water with the hot-water/water mixing ratio applied on the initial set temperature is effected. According to this method, the fluctuation of temperature of mixed hot-water upon using it intermittently can be restrained and hot-water having a stabilized temperature can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water temperature fluctuation suppressing method for suppressing fluctuation of hot water temperature when intermittently using a hot water supply apparatus.

[0002]

2. Description of the Related Art Recently, there is a hot water supply apparatus in which hot water mixing means is provided on the downstream side of a heat exchanger so as to obtain hot water having a desired hot water temperature by changing a mixing ratio of hot water and water. .

[0003]

However, in actuality, in such a hot water supply apparatus, the hot water outlet temperature fluctuates due to various factors. In particular, if it is used intermittently, there is a drawback that the temperature of the tapping water changes. For example, as shown in FIG. 2, the hot water temperature of hot water to be tapped fluctuates instantaneously when the tapping is restarted after the tapping is stopped. For example, after stopping hot water for 30 seconds,
When the operation is started, the supply rate of cold water increases due to ignition delay of the gas burner, etc., and so-called undershoot occurs in which the temperature of the hot water to be tapped temporarily lowers as compared with the set hot water temperature. Further, when the operation is started after the hot water supply is stopped for 3 minutes, overshoot occurs at the start of the operation due to post-boiling. It is known that the above-mentioned undershoot and overshoot differ depending on the temperature of cold water supplied to the hot water supply device, in addition to the hot water discharge stop time (water stop time).

Therefore, the present invention focuses on this point, and knows the presence or absence and the magnitude of the fluctuation of hot water caused by the water stop time or the temperature of the cold water, and depending on the water stop time and the temperature of the cold water during intermittent use. It is an object of the present invention to provide a hot water temperature fluctuation suppressing method in which hot water is discharged by changing the hot water mixing ratio related to the set hot water temperature to suppress fluctuations in the hot water temperature.

[0005]

In order to solve the above-mentioned problems, the present invention comprises a hot water mixing means connected to the hot water outlet side of a heat exchanger, and a water supply pipe leading to the water introduction side of the heat exchanger. In a hot water supply device that forms a water supply branch pipe that branches from the hot water mixing means to the hot water mixing means, when the hot water supply device operates intermittently based on the set hot water temperature, the fluctuation of the hot water temperature specific to the hot water supply device from the hot water stop time The presence or absence of the hot water and the size of the hot water are adjusted, and the hot water mixing ratio of the hot water mixing valve is adjusted to change the set hot water temperature within the specified temperature range. After that, the hot water mixing ratio of the hot water mixing valve is returned to the initial ratio. Further, according to the present invention, the set hot water temperature is changed within a predetermined temperature range by determining whether or not there is a change in the hot water temperature peculiar to the hot water supply device depending on the temperature of the cold water supplied to the hot water supply device together with the hot water supply stop time described above. Adjust the hot water mixing ratio of the hot water mixing valve to do so, perform hot water again at the hot water mixing time after changing the hot water stop time and the time corresponding to the cold water temperature,
After that, the warm water mixing ratio of the warm water mixing valve is returned to the initial ratio.

[0006]

When the hot water supply device is intermittently operated on the basis of the set hot water temperature, the presence or absence and the magnitude of the change in the hot water temperature peculiar to the hot water supply device are determined from the hot water supply stop time. Next, the hot water mixing ratio of the hot water mixing valve is adjusted to change the set hot water temperature within a predetermined temperature range, a time corresponding to the hot water stop time is set, and the hot water mixing ratio is changed again for that time. I do. Then, the warm water mixing ratio of the warm water mixing valve is returned to the initial ratio. Further, the temperature of the cold water supplied to the hot water supply device can be detected together with the hot water supply stop time described above, and it can be used for determining whether or not there is a change in the hot water temperature and the size thereof.
Based on the presence / absence of such fluctuation and the judgment of the magnitude, set the hot water stop time and the time corresponding to the temperature of the cold water, and again perform hot water discharge at the changed hot water mixing ratio for that time, and mix the hot water of the hot water mixing valve. Try to return the ratio to the original ratio.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hot water supply apparatus for carrying out the hot water temperature fluctuation suppressing method according to the present invention will be described below with reference to the accompanying drawings. In FIG. 1, reference numeral 1
Indicates a hot water supply device, and the hot water supply device 1 is configured such that hot water temperature detecting means, that is, hot water mixing means 5 is connected to the hot water outlet side 3 of the heat exchanger 2 via a hot water temperature thermistor 4, and 2, a water supply pipe 7 reaching the water introduction side 6 is branched to form a water supply branch pipe 8 reaching the hot water mixing means 5, and the incoming water temperature thermistor 9, the running water switch 10, and the pressure of the supplied cold water are supplied to the water supply pipe 7. A mixed temperature thermistor 12 is provided on the mixed hot water outlet side 3 of the hot water mixing means 5 with a water governor 11 kept substantially constant therebetween.

The hot water outlet thermistor 4, the hot water mixing means 5, the incoming water temperature thermistor 9, the flowing water switch 10 and the mixed temperature thermistor 12 in the hot water supply apparatus 1 are electrically connected to the controller 13. In addition, the controller 13
Remote operation means 14 for operating the hot water supply device 1 and setting the hot water discharge temperature is connected. Reference numeral 15 indicates a gas burner.

Now, the hot water mixing means 5 will be described. The hot water mixing means 5 has a function of mixing cold water introduced from the water supply branch pipe 8 and hot water introduced from the hot water outlet side 3 of the heat exchanger 2 and discharging hot water as mixed hot water. It has an adjusting mechanism (not shown). That is, a signal relating to the hot water temperature set by the remote control means 14 is given to the controller 13, and a valve opening adjustment signal is given from the controller 13 to the valve opening adjusting mechanism. A thermal expansion member is provided in the valve opening adjustment mechanism, and fluctuations in the hot water temperature and water temperature of inflowing hot water are adjusted by adjusting the valve opening by expanding and contracting the volume of the thermal expansion member. The ratio is automatically corrected.

Next, the controller 13 will be described. The controller 13 gives a control signal to the components of the hot water supply device 1 by a signal from the remote operation means 14 or turns on the running water switch 10 by passing cold water through the water supply pipe 7 to supply fuel gas to the gas burner 15. The supplied water is supplied and an ignition means (not shown) is operated to ignite, and the incoming water temperature thermistor 9 and the outgoing hot water temperature thermistor 4 detect the cold water temperature and the outgoing hot water temperature, and the outgoing hot water temperature is substantially based on these detection signals. It has a function of applying a flow rate adjusting signal to a gas flow rate adjusting valve (proportional valve) for supplying gas to the gas burner 15 so as to maintain a constant value, and performing combustion adjustment.

Further, the controller 13 measures the time from the turning off of the running water switch 10 to the turning on of the hot water switch 10 as the time from the stop of hot water discharge to the hot water discharge again (water stop time), and undershoots from this water stop time. It is determined whether or not an overshoot has occurred, and when an undershoot has occurred, the hot water mixing ratio of the hot water mixing means 5 is changed to change the hot water discharge temperature to a predetermined temperature (for example, 1 to 6 ° C.). )
On the other hand, when overshooting occurs, a procedure for changing the hot water mixing ratio to lower the hot water discharge temperature to a predetermined temperature (for example, 1 to 6 ° C.) by the set temperature is executed. Is. It should be noted that the above 1 to 6 ℃
This value is unique to the water heater 1, and the degree of undershoot and overshoot changes depending on the water stop time, so a value that is most suitable for the water stop time is selected. Further, the controller 13 adjusts the time (1 to 10 seconds) at which hot water is discharged at the changed hot water mixing ratio in accordance with the water stoppage time, and then adjusts the hot water mixing ratio at the initial set temperature. Perform the steps to return to. The value of 1 to 10 seconds is an appropriate value that can be selected according to the stoppage time. The means for executing the above procedure is appropriate.

The hot water supply apparatus for carrying out the hot water temperature fluctuation suppressing method according to the present invention is constructed as described above, and its operation will be described below. First, the temperature of hot water discharged from the remote control means 14 is set in advance.
The signal related to this setting is introduced into the controller 13, and the controller 13 outputs a control command to the hot water mixing means 5 to adjust the mixing ratio so as to correspond to the set hot water temperature. After the operation is started, the cold water passes through the water supply pipe 7 to turn on the running water switch 10, supply the fuel gas to the gas burner 15 and ignite it, and the heat exchange by the heat exchanger 2 is started.
At this time, the controller 13 sends a gas flow rate adjusting signal to the gas flow rate adjusting valve of the gas burner 15 so that the temperature of the hot water discharged from the heat exchanger 2 becomes substantially constant by the detection signals of the incoming water temperature thermistor 9 and the hot water temperature thermistor 4. And adjust the combustion.

Next, when hot water is introduced into the hot water mixing means 5 from the hot water outlet side 3 of the heat exchanger 2, a predetermined amount is supplied according to the cold water supplied from the water supply branch pipe 8 of the water supply pipe 7 and the valve opening degree. Are mixed at a ratio of to obtain mixed hot water having the set hot water temperature. In this case, the thermal expansion member provided in the valve opening adjustment mechanism of the hot water mixing means 5 causes a volume change when the mixed hot water temperature fluctuates, and adjusts the opening degree of the valve body so as to reach the set hot water temperature. Then, the mixing ratio of the hot water and the cold water is corrected, so that the fluctuation of the mixed hot water during the continuous operation is suppressed.

The hot water temperature of the mixed hot water discharged is detected by the mixed temperature thermistor 12, the detection signal is given to the controller 13, and the valve opening adjustment signal is sent to the valve body opening adjustment mechanism of the hot water mixing means 5. Given. In this way, mixed hot water having the set hot water temperature can be obtained.

In the normal continuous hot water supply operation as described above, mixed hot water having a desired hot water temperature can be obtained even if there is fluctuation in cold water, but here, the operation for intermittent operation is performed. Will be explained. When the hot water is stopped, the water flow switch 10 is turned off, the gas flow rate adjusting valve of the gas burner 15 is turned off, and the combustion of the gas burner 15 is stopped. Controller 1
3 starts timing. Next, when the hot water supply operation is started again, the running water switch 10 is turned on, and the controller 13 stops the time measurement to stop the water. The controller 13 determines whether an undershoot or an overshoot has occurred based on the water stop time. For example, if the water stop time is 30 seconds, it is assumed that an undershoot has occurred, and the hot water mixing ratio of the hot water mixing means 5 is changed so that the hot water outlet temperature becomes higher by a predetermined temperature (for example, 1 to 6 ° C.) depending on the set temperature. To On the other hand, if the water stoppage time is 3 minutes, it is determined that an overshoot has occurred, and the hot water mixing ratio is changed to lower the hot water discharge temperature by a predetermined temperature (for example, 1 to 6 ° C.) according to the set temperature.

The controller 13 is the running water switch 10
After turning on, the time from which hot water is discharged at the changed hot water mixing ratio is set to 1 to 10 in correspondence with the above-mentioned stoppage time.
Select from the seconds, and then return to the hot water mixing ratio required for the initial set temperature. Therefore, undershoot and overshoot are absorbed, and it becomes possible to supply hot water having a stable hot water temperature.

The embodiment of the hot water supply apparatus for carrying out the hot water temperature fluctuation suppressing method according to the present invention has been described above.
The controller 13 of the hot water supply device 1 determines whether an undershoot or an overshoot has occurred based on the temperature from the stop of hot water discharge to the hot water discharge again (stop water time) and the temperature of the cold water detected by the incoming water temperature thermistor 9. It is also possible to execute a procedure of determining whether or not the degree of undershoot or overshoot. That is, the hot water mixing ratio of the hot water mixing means 5 is corrected to increase or decrease a more appropriate predetermined temperature (for example, 1 to 6 ° C.) according to the incoming water temperature detected by the incoming water temperature thermistor 9.

According to this hot water temperature fluctuation suppressing method, it becomes possible to synergistically suppress the fluctuation of the hot water temperature.

[0019]

As described above, according to the present invention, fluctuations in the hot water temperature of the mixed hot water during intermittent use can be suppressed, and stable hot water can be obtained.

[0020]

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a hot water supply device according to the present invention.

FIG. 2 is a diagram showing characteristics of hot water discharge temperatures of the hot water supply apparatus according to the present invention and the related art.

[Explanation of symbols]

 1 Hot water supply device 2 Heat exchanger 3 Hot water outlet side 4 Hot water temperature thermistor 5 Hot water mixing means 6 Water introduction side 7 Water supply pipe 8 Water supply branch pipe 9 Inlet water temperature thermistor 10 Water switch 11 Water governor 12 Mixed temperature thermistor 13 Controller 14 Remote operation Means 15 Gas burner

Claims (2)

[Claims] 1. Hot water supply wherein hot water mixing means is connected to the hot water outlet side of the heat exchanger, and a water supply branch pipe is branched from a water supply pipe reaching the water introduction side of the heat exchanger to the hot water mixing means. When operating the system intermittently based on the set hot water temperature, the presence or absence of fluctuations in the hot water temperature unique to the hot water supply device is judged from the hot water supply stop time, and the set hot water temperature is within the specified temperature range. The hot water mixing ratio of the hot water mixing valve is adjusted to change the hot water mixing ratio, and hot water mixing is performed again at the changed hot water mixing ratio for a time corresponding to the hot water stop time, and then the hot water mixing ratio of the hot water mixing valve is changed to the initial ratio. The method for suppressing fluctuations in hot water temperature is characterized in that 2. The hot spring stop time according to claim 1,
Whether or not the hot water temperature peculiar to the hot water supply device varies depending on the temperature of the cold water supplied to the hot water supply device, the size is determined, and the hot water mixing ratio of the hot water mixing valve is adjusted to change the set hot water temperature within a predetermined temperature range, Hot water is re-launched with the changed hot water mixing ratio for a time corresponding to the hot water stop time and the temperature of cold water, and then the hot water mixing ratio of the hot water mixing valve is returned to the initial ratio. Temperature fluctuation suppression method.