JPH0411770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hot water outlet temperature control device for an instantaneous water heater.

(Prior art and its problems) Recently, in instantaneous water heaters, in order to stabilize the hot water temperature, the burner is set based on the hot water temperature set by the user and the hot water temperature detected by a thermistor, etc. This is a so-called proportional control type in which the combustion amount is adjusted by controlling the amount of gas supplied to the combustion chamber.

However, with this type of conventional system, the control amount is cleared once the hot water tap is stopped, and the next time the hot water tap starts, the control goes through a predetermined process again, so the hot water temperature remains stable from the start of hot water tap. It takes a relatively long time to reach the desired temperature, and if the same person or different people repeatedly start and stop hot water under similar hot water supply conditions, it will take a long time to stabilize at the desired temperature, which is a major inconvenience in use. There is a problem with feeling.

The present invention aims to solve the above-mentioned conventional problems.

(Means for Solving the Problems) The configuration of the present invention will be explained based on FIGS. 1 and 2 corresponding to the embodiment. 2 and a hot water temperature detection means 3, a control means 5 for controlling the amount of gas supplied to the burner 4 of the water heater, and a hot water temperature setting means 6 are provided, and the control means 5 has a storage means for storing the amount of gas supplied. 7, a proportional control means 8 for controlling the amount of gas supplied based on the set hot water temperature and the detected hot water temperature, and a memory control means 9 based on the stored gas amount to be supplied, which of these means 8 and 9 should be adopted? A selection means 10 for selecting is provided, and the selection means 10 includes an OFF time judgment for determining whether the OFF time from when the water switch 2 is turned OFF to when it is next turned ON is within a predetermined time _t1 . means 11, hot water supply condition change determination means 12 for determining whether or not changes in the set hot water temperature and the amount of hot water are within a predetermined range; and a hot water supply condition change determination means ₁₂ for determining whether or not the change in the set hot water supply temperature and the amount of hot water supplied is within a predetermined range; A storage control time judgment means 13 is provided to judge whether or not there is a memory control time, and these judgment means 11, 12, 13
Therefore, when the running water switch 2 is turned off and then turned on again, it is turned off for a predetermined time t2, provided that the OFF time is within a predetermined time _t1 and the change in hot water tap conditions is within a predetermined _range . The configuration is such that the storage control means 9 is selected.

Next, the embodiment shown in FIG. 1 will be described. Reference numeral 14 indicates a heat exchanger for a water heater, and a running water switch 2 is provided on the upstream side of the heat exchanger, and a hot water temperature detecting means 3 is provided on the downstream side. The specific configuration of is arbitrary.
Reference numeral 15 is a control valve that is controlled by the control means 5 to control the amount of gas to be supplied, and its configuration may be appropriate. Next, reference numeral 16 indicates the running water switch 2,
A general representation of the input section for signals from the hot water temperature detection means 3 and the hot water temperature setting means 6, and reference numeral 1
Reference numeral 7 indicates a storage means for storing the set hot water temperature.
Including the above configuration, each component of the control means 5 may be configured by an independent electronic circuit or the like, or may be configured as firmware using a microcomputer.

(Function) In the above configuration, hot water is continuously tapped, and the water flow switch 2 is turned on for more than the predetermined time _t2 .
In this case, the selection means 10 selects the proportional control means 8, and thus the hot water temperature set by the hot water temperature setting means 6 and the hot water temperature detection means 3
The control valve 15 is operated to control the amount of gas supplied to the burner 4 based on the detected hot water temperature, that is, proportional control similar to the conventional method is performed, and hot water can be tapped at a stable temperature. The amount of gas supplied during this operation is stored in the storage means 7 every moment and updated.

Next, stop the above hot water taps and turn on the running water switch 2.
When it becomes OFF, the OFF time determination means 11
Measurement of OFF time starts. However, this
If the OFF state continues for a longer time than the predetermined time t ₁ set in the OFF time determining means 11 and then becomes the ON state again, the OFF time determining means 11 determines that the selecting means 10 The proportional control means 8 is selected again, and proportional control similar to that described above is started.

When the above-mentioned OFF state returns to the ON state before the elapse of the predetermined time _t1 , the selection means 10 determines that the change in the set hot water tap temperature and hot water output amount is within a predetermined range, that is, the above-mentioned Flowing water switch 2
When the is turned ON again, the memory control is performed on the condition that the user does not change the set temperature and the amount of hot water set in the hot water temperature setting means 6, or even if the change is made, the temperature remains within a predetermined range. Select means 9. The hot water tap condition change determining means 12 determines whether or not such conditions are satisfied.

When the memory control means 9 is selected in this way, the control means 9 operates the control valve 14 so as to supply the burner 4 with an amount of gas equal to the supply gas amount stored in the memory means 7 . In this way, the same amount of gas as the amount of gas supplied during the previous use is supplied to the burner, so that the outlet temperature can be immediately made the same as that during the previous use. Such control is continued until the storage control time determining means 13 determines that a predetermined time _t2 has elapsed, and this predetermined time
When t ₂ has elapsed, the selection means 10 selects the proportional control means 8 and shifts to proportional control. Of course,
Even before the predetermined time _t2 has elapsed, the user changes the set temperature in the hot water tap temperature setting means 6 or changes the hot water output amount, and the hot water tap condition change determination means 12 detects a change in hot water tap condition. If it is determined, proportional control will be performed.

In this way, the maximum memory control time is the predetermined time t ₂
, and even within this time, the proportional control is shifted to as necessary, so the function as a proportional control type water heater is not diminished. In addition, in the above explanation, the amount of supplied gas to be stored in the storage means 7 is as follows:
In addition to representing the amount of gas to be supplied, it also refers to any appropriate signal, such as an opening signal of the control valve 15, which substantially represents the amount of gas to be supplied.

(Embodiment) The flowchart in FIG. 2 shows an example of the process flow when the configuration of the present invention is realized using a microcomputer. To explain the flow,
First, in the step, the running water switch 2 is turned on.
It is determined whether it is in the ON state or not, and if it is in the OFF state, it goes through the steps of measuring the OFF time and canceling the selection flag, and then returns to the step. Thereby, it is possible to measure the time elapsed since the switch was turned off. In the next step, if the running water switch 2 is in the ON state, the process proceeds to step. In this step, the state of the selection flag is determined, and if it is set, that is, if it is in the ON state during proportional control,
Branches in the direction of continuation of proportional control. In addition, if the selection flag is cleared, that is, the running water switch 2
When the state changes from the OFF state to the ON state, the process branches to the storage control direction. Then, in the sequential steps, the OFF time of the water switch 2 is changed to a predetermined time t ₁
whether the change in the set hot water temperature value at the step is within the predetermined temperature range ±t℃, and whether the change in the amount of hot water output at the step is within the range, and satisfy these. In this case, memory control is performed in the step. If each of these conditions is not satisfied, the process goes through the step of setting a selection flag and then goes to the step of proportional control.

After the memory control step 8, there is a step for determining the memory control time, and in this step, if the memory control time is within the predetermined time _t2 ,
The process returns to the step described above, and when the predetermined time _t2 has elapsed, the process returns to the step of proportional control via the step described above.

On the other hand, after the proportional control step, there is a step of storing the set hot water temperature value in the memory element (RAM), and a step of storing the current supply gas amount in the memory element.
Return to the previous step.

Note that the process of determining the change in the amount of hot water dispensed in the above step can be carried out by providing a flow rate detection means (not shown) at an appropriate location in the hot water supply system 1 and directly determining the change based on the flow rate detection signal. Appropriate methods are applied, such as instantaneously giving the minimum amount of gas when igniting the burner 4, determining the temporal change in the value of the hot water temperature detection means 3 at that time, and indirectly determining the flow rate based on this. It is possible.

(Effects of the Invention) As described above, in a proportional control instantaneous water heater, if hot water is temporarily stopped and hot water is restarted before a predetermined time elapses, the set hot water Provided that the changes in temperature and amount of hot water are within a predetermined range, an amount of gas equal to the amount of gas supplied immediately before stopping hot water tap is supplied to the burner based on the memory, so the hot water temperature will quickly return to the temperature at that time. stipulated,
Therefore, when the same person or different people repeatedly supply and stop hot water under similar hot water supply conditions, hot water can be quickly and stably supplied at the desired temperature, resulting in a good feeling of use. . In addition, the control time based on such memory is limited to a predetermined time at the longest, and even within this time it shifts to proportional control as necessary, so the function of the water heater as a proportional control type water heater is not diminished. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a system explanatory diagram schematically showing the configuration of the present invention, and FIG. 2 is a flowchart showing an example of the flow of processing when the configuration of the present invention is realized using a microcomputer. Code 1...Hot water supply system, 2...Water switch, 3...Temperature detection means, 4...Burner, 5...Control means, 6
... Hot water temperature setting means, 7, 17... Memory means, 8...
Proportional control means, 9... Memory control means, 10... Selection means, 11... OFF time judgment means, 12... Hot water supply condition change judgment means, 13... Memory control time judgment means, 1
4... Heat exchanger, 15... Control valve, 16... Input section.

Claims (1)

[Claims] 1. A hot water supply system of an instantaneous water heater is provided with a running water switch and a hot water temperature detection means, and a control means for controlling the amount of gas supplied to the burner of the water heater and a hot water temperature setting means, and the control means includes a hot water temperature setting means. Proportional control means which is provided with a storage means for the supply gas amount and controls the supply gas amount based on the set hot water tap temperature and the detected hot water tap temperature; and a storage control means based on the stored gas supply gas amount;
A selection means is provided for selecting which of these means to take, and the selection means includes a running water switch.
OFF time judgment means that judges whether the OFF time from turning OFF to turning ON is within a predetermined time, and judges whether changes in the set hot water temperature and hot water output amount are within a predetermined range. A hot water tap condition change determining means and a memory control time determining means for determining whether the elapsed time after selecting the memory controlling means is less than or equal to a predetermined time are provided, and these determining means
When the running water switch is turned off and then turned on again, the memory control means is selected for a predetermined period of time, provided that the off time is within a predetermined period of time and the change in hot water supply conditions is within a predetermined range. This is a hot water temperature control device for an instantaneous water heater.