JP3034754B2 - Hot water supply temperature control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply temperature control apparatus which enables hot water to be supplied at a predetermined temperature at the start of hot water supply.

[0002]

2. Description of the Related Art Conventionally, fuel supply and combustion and heating of a heat exchanger by this combustion have been carried out in parallel by a tapping operation such as opening of a water faucet. 2. Description of the Related Art Water heaters that automatically control a hot water temperature to a preset value based on an output of a hot water temperature sensor or a hot water temperature sensor provided on a hot water side are widely used. In such a water heater, hot water heated to the set temperature in the heat exchanger is automatically discharged by a tapping operation, for example, opening of the faucet as described above.

[0003] In this case, when the hot water supply time is long, for example, when the faucet is repeatedly opened and closed relatively frequently, the water in the piping is heated by the heat of the heat exchanger even after the tapping is completed. There is a relatively hot water supply from the beginning of the tap reopening.On the other hand, if the hot water supply is started after a considerable time, the temperature will be low at the beginning of the tapping by the tap reopening, but thereafter The intended heating control of the heat exchanger is performed accordingly.

[0004]

Since the conventional water heater is configured as described above, it is possible to control the tapping temperature, but if a certain amount of time has not elapsed since the previous tapping was completed. In addition, since the water temperature in the pipe is increased by the amount of heat held by the heat exchanger, the feedforward tapping control at the time of tapping again cannot be performed properly due to a difference between the detected value of the inlet water temperature sensor and the true value. There were problems such as.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and stably controls a tapping temperature at which a target tapping temperature can be obtained without being affected by an output fluctuation of a tap water temperature sensor. It is an object to obtain a hot water supply temperature control device that can be implemented.

[0006]

A hot water supply temperature control apparatus according to the present invention is characterized in that the control means controls the operation from hot water supply to re-hot water supply.
If the time is longer than the predetermined time setting,
Control is performed based on the incoming water temperature.
Is shorter than the time setting value and the integrated flow rate is
If the flow rate setting value is not reached, immediately before the end of the previous bath
Hot water control based on the incoming water temperature
Things.

[0007]

[Action] hot water temperature control device in the present invention, the last
The set time has yet to elapse from the end of hot water to the hot water this time.
And the accumulated flow rate of hot water has reached the set flow rate this time.
If not, the water temperature data at the end of the last hot water
By performing hot water discharge control based on
Stabilization of feedforward control and hot water supply
Make temperature stabilization feasible.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an incoming water temperature sensor which is provided on the incoming side of a heat exchanger in a water heater and detects an incoming water temperature, and 2 denotes at least the incoming water temperature of the incoming water temperature detected by the incoming water temperature sensor 1 immediately before the end of outgoing water. Memory to store
3 is a tie that measures the time from the end of tapping to the tapping again.
Reference numerals 4 and 4 denote flow rate sensors for measuring the integrated flow rate of incoming water after the start of tapping.

[0009] 5 in the microprocessor (controller), if the time is not longer than the predetermined time set value, to perform the hot water control based on the current output value of the incoming water temperature sensor 1, the The time is shorter than the time set value above,
In addition, when the integrated flow rate does not reach the flow rate set value, it functions to control hot water supply based on the incoming water temperature immediately before the end of the previous hot water supply.

Further, reference numeral 6 denotes a temperature setting device for arbitrarily setting the tapping temperature, 7 a tapping temperature sensor for detecting the tapping temperature, and 8 a proportional control for controlling the flow rate of the fuel based on the operation result of the microprocessor 5. It is a valve.

FIG. 2 is an explanatory view showing a schematic configuration of the water heater. Reference numeral 11 denotes a heat exchanger connected to a water pipe 12, which guides heated hot water to a faucet (not shown). On the water inlet and outlet sides of the heat exchanger 11, the above-mentioned hot water temperature sensors 7, such as an upper water temperature sensor 1, a flow rate sensor 4, and a hot water temperature thermistor, are installed.

Reference numeral 13 denotes a fuel pipe for supplying a fuel gas. One end of the fuel pipe 13 is connected to a combustor 14 facing the lower part of the heat exchanger 11. The proportional valve 8 for adjusting the amount is provided.

Next, the operation will be described with reference to the flowchart of FIG. First, in controlling hot water supply temperature, a desired tapping temperature is set in advance by the temperature setting device 6, and the faucet is opened. Thereby, water enters the heat exchanger 11 through the water pipe 12.

Further, based on the temperature setting input of the temperature setting device 6 and the like, the opening control of the proportional valve 8 is performed, and fuel is supplied to the combustor 14 through the fuel pipe 13.
The fuel is ignited, the fuel is burned, and the heat exchanger 11 is heated.

For this reason, the water in the heat exchanger 11 is heated to a temperature at which the above-mentioned set temperature is obtained, and is discharged from the faucet.
In the present invention, the following hot water supply temperature control is performed under the control of the microprocessor 5 based on the detection output of the incoming water temperature sensor 1 on the incoming side of the heat exchanger 11.

That is, first, when a heat request is made in response to a faucet opening operation or the like (step ST1), the microprocessor 5 starts hot water supply control (step ST1).
2). In this hot water control, the temperature set by the temperature setter 6 is set in accordance with PID control or the like based on detection output data of the hot water temperature sensor 1 and the hot water temperature sensor 7 and the like.

Here, when a heat request stop command is issued (step ST3), the memory 2 stores the microprocessor 5
Immediately before the end of tapping at this time, the incoming water temperature sensor 1
Is stored (step ST)
4) Subsequently, the tapping control is stopped (step ST)
5).

When the tapping control is stopped, the time from the stop to the next tapping is measured by the timer 3 (step ST6). If there is a heat request for tapping (step ST7), The microprocessor 5 determines whether or not the time t _s to the hot water exceeds a predetermined time set value t _c (step ST8).

[0019] As a result of this determination, the time t _s is time set value t
if it exceeds _c takes the output value T _i of the current incoming water temperature sensor 1 (step ST9), based on this, the microprocessor 5 will implement the desired leaving water temperature control (step ST10).

Even when the time t _s does not exceed the time set value t _c , when the flow rate detection value F _s of the water after the start of tapping by the flow rate sensor 4 exceeds the flow rate set value F _c , step ST11), based on the current of the output value T _i, the hot water temperature control is performed. In this way, when the heat request is stopped (step ST12), the processing from step ST4 is executed thereafter. If the heat request has not been stopped, the process from step ST11 is executed.

Meanwhile, in step ST11, the integrated flow rate F _s If it is determined that less than the flow rate setting value F _c (step ST11), the detection output data T of the incoming water temperature sensor 1 of the previous tapping immediately before the end _ib is taken in (step ST13), and based on this, that is, hot water supply control is performed based on data taking into account the water temperature heated by the residual heat of the heat exchanger (step ST10). Execute.

In the above embodiment, the tapping control based on the current tapping temperature is performed when the time from the end of tapping to the tapping again or the integrated flow rate of tap water from the start of tapping exceeds a predetermined set value. However, if the hot water flows little by little, before the remaining hot water can be removed from near the feedwater temperature detection sensor,
Since the above time elapses, it is most appropriate to control based on the integrated flow rate.

[0023]

As described above, according to the present invention, the control
By means, the time from hot water to hot water again was predetermined
If the time is longer than the set time, the
Hot water control is performed.
Shorter and the accumulated flow reaches the set flow rate
If not, the water temperature based on the temperature just before
So that the hot water supply control is performed.
The target tap temperature can be obtained without being affected by sensor output fluctuations.
That can stably perform the hot water control
There is fruit.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a hot water supply temperature control device according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a water heater used for hot water temperature control according to the present invention.

FIG. 3 is a flowchart showing a hot water supply temperature control procedure according to the present invention.

[Explanation of symbols]

 1 Inlet water temperature sensor 2 Memory 3 ThailandMa  4 Flow sensor 5 Microprocessor (control means) 11 Heat exchanger

Claims (1)

(57) [Claims] 1. An incoming water temperature sensor provided on a water inlet side of a heat exchanger in a water heater for detecting an incoming water temperature, and among the incoming water temperatures detected by the incoming water temperature sensor, at least an incoming water temperature immediately before the end of the outgoing water is stored. Memory and from the start of hot water
A flow rate sensor for measuring the integrated flow rate of incoming water, a clock means for measuring the elapsed time from the end of the previous hot water supply, and a hot water supply control based on the current incoming water temperature when the elapsed time is longer than a predetermined set value. The elapsed time.
Set value that is shorter than the fixed value and the integrated flow rate is a predetermined value
If the temperature of the hot water is not reached, the hot water supply temperature control device includes control means for performing hot water supply control based on the incoming water temperature immediately before the end of the last hot water stored in the memory.