JPH0212336B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a hot water storage type water heater.

Configuration of conventional example and its problems As shown in FIG.
The hot water in the hot water storage tank 2 is heated to a preset boiling temperature by controlling the output from the hot water storage tank 2. At this time, the boiling temperature setting is mostly fixed at a certain value, and the hot water supply load varies depending on the family structure, life cycle, and lifestyle of individual households, as well as differences in weather conditions such as region and season. The disadvantage is that there is a lot of hot water remaining in the hot water storage tank 2, especially when there is a small family or when the hot water supply load decreases, resulting in an increase in the amount of heat dissipated and a significant drop in equipment efficiency. It had

Purpose of the invention The present invention solves such conventional problems,
The objective is to respond to fluctuating hot water supply loads and minimize the amount of remaining hot water, thereby increasing equipment efficiency and providing a water heater that is highly energy efficient.

Structure of the Invention To achieve this object, the present invention provides a hot water storage tank, a heater for heating water in the hot water storage tank, a hot water temperature detection means for detecting the temperature of hot water in the hot water storage tank, and a hot water storage tank. a heating time detection means that operates when the water temperature in the water is above a preset reference temperature and detects the heating time within a certain period up to the present time; and a calculation that calculates the boiling temperature setting based on the heating time. and a control device that controls the heater based on the output of the hot water temperature detection means and the boiling temperature set by the calculation device.

With this configuration, the heating time during a certain period when the water temperature is higher than a certain reference temperature is detected, and based on this heating time, the value of the boiling temperature setting is calculated and the heater is controlled. This has the effect of responding to hot water supply loads that fluctuate depending on differences in family structure, life cycle, and lifestyle, as well as region and climate.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

In FIG. 2, a heater 1, a hot water storage tank 2, a hot water temperature sensor 3 as a hot water temperature detecting means, a timer 4 as a heating time detecting means, an arithmetic device 5 for calculating a boiling temperature setting based on the heating time, and the above-mentioned Based on the output from the hot water temperature sensor 3 and the calculation device 5, the heater 1
A control device 6 for controlling the operation of the timer 4 and the timer 4 is provided.

FIG. 3 shows a control block diagram, and a case will be described in which the boiling temperature setting for the next day is determined based on the heating time of the previous day.

First, the boiling temperature setting T _set is set to an initial value T _ioit .

After the water heater starts operating, when the hot water temperature sensor 3 detects that the water temperature in the hot water storage tank 2 has reached a certain reference temperature T _st , the timer control circuit 7 in the control device 6 starts the timer 4. Start the operation. Thereafter, when the water temperature reaches the boiling set temperature T _set = _Tioit , the heater control circuit 8 stops the operation of the heater 1, and at the same time, the timer control circuit 7 stops the timer 4 from counting the heating time. Therefore, the heating time counted is when the water temperature is T _st
This is the time when T set (= T ioit ) changes from T _set (= T _ioit ). This heating time is input to the calculation device 5, which calculates the next day's boiling temperature setting T _set and replaces it with T _ioit . Thereafter, the above operation is repeated every day according to the calculated boiling temperature setting T _set .

Here, a method of calculating the boiling temperature setting will be described. In FIG. 4, the following relationship holds true.

CVs (Ts − Tc) = εCV _H (Tset − Tc) --(a) or CVs (Ts − Tc) = εQh --(b) where, V _s : Water supply amount T _s : Water supply temperature T _c : Water supply Temperature ε: Efficiency (heat exchange, etc.) V _H : Storage amount T _set : Set boiling temperature Q: Amount of heat supplied per unit time h: Heating time c: Specific heat Here, using the reference temperature T _st above, (a) Transforming the right side of the equation, εCV _H (Tset−Tc)=εCV _H (Tset−Tst)
+εCV _H (Tst－Tc) --(c) Also, equation (b) is: εQh=εQhA+εQhB --(d) Where, hA: Time required to raise the water temperature in the tank from T _c to T _st hB: Time required to raise the water temperature in the tank from T _st to T _set Furthermore, since (c) = (d), Tset = Tst + Qh _A + Qh _B −CV _H (Tst − Tc) / CV _H --(e) Here Since Qh _A = CV _H (Tst−Tc) --(f), we obtain Tset=Tst+Qh _B /CV _H --(g).

Here, the initial value of the tank water temperature on a certain day is Tst.
Even if it is higher, hB uses the same time.

In this example, except for the period from Tc to Tst of the previous day,
By detecting the heating time h _B until Tset,
The boiling set temperature T _set for the next day is calculated and the heater 1 is controlled.

Therefore, even when the hot water supply load changes depending on the season, the set boiling temperature is determined based on the heating time (=heat amount supplied) for that season, so the amount of remaining hot water can be reduced and energy savings can be achieved.

Also, for the calculated boiling temperature setting,
Upper and lower limits are set to prevent dangers such as increased heat dissipation and boiling caused by setting the boiling temperature too high, and conversely to prevent dangers such as boiling that may become unusable due to being set too low. This prevents dissatisfaction among the public.

Effects of the Invention According to the water heater of the present invention, the following effects can be obtained.

(1) The amount of heat input to the water heater or the amount of hot water supplied under the current usage status is detected and the boiling water temperature is calculated according to the required amount of hot water actually used, so the personnel composition of each individual family can be calculated. This allows for fine-grained control that is always tailored to the user's usage patterns, responding to differences in people's lives, family life cycles, and lifestyle changes within a single household. In particular, when the hot water supply load is small, the amount of remaining hot water is suppressed, and energy-saving operation with high equipment efficiency is possible.

(2) Since it is possible to control according to usage conditions, hot water supply performance is not affected by differences in weather conditions from year to year.

(3) Since the equipment is controlled according to the required amount of hot water even when used in different regions, the same configuration can be used in any region, achieving detailed control at low cost.

(4) By setting upper and lower limits for the boiling temperature set calculated from the heating time, it is possible to prevent an increase in heat radiation or danger due to the boiling temperature set being too high, and to prevent dangers caused by the boiling temperature set being too high. It does not become unusable for a certain purpose or cause user dissatisfaction.

(5) If the configuration is such that the heating time detection starts when the temperature inside the hot water storage tank reaches a certain reference value,
When calculating the boiling temperature setting, there is no problem even if the feed water temperature is unknown, and therefore, there is no need to detect the feed water temperature, resulting in cost reduction.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the configuration of a conventional water heater;
FIG. 2 is a schematic diagram of a water heater according to an embodiment of the present invention, FIG. 3 is a block diagram of a control portion of the same, and FIG. 4 is an explanatory diagram of a calculation method by an arithmetic unit of the same. DESCRIPTION OF SYMBOLS 1... Heater, 2... Hot water storage tank, 3... Hot water temperature sensor as means for detecting hot water temperature, 4... Timer as means for detecting heating time, 5... Arithmetic unit, 6...
Control device.

Claims (1)

[Scope of Claims] 1. A hot water storage tank, a heater for heating water in the hot water storage tank, a hot water temperature detection means for detecting the temperature of hot water in the hot water storage tank, and a hot water temperature in the hot water storage tank that is set in advance. a heating time detection means that operates at or above a set reference temperature and detects the heating time within a certain period up to the current time; a calculation device that calculates the boiling temperature setting based on the heating time; and the water temperature detection means. A water heater comprising: a control device that controls the heater based on the output of the means and the value of the boiling temperature set by the arithmetic device. 2. The calculation device has an upper limit value and a lower limit value for the boiling temperature setting, and if the calculated boiling temperature setting exceeds the upper limit value or the lower limit value, it changes the boiling temperature setting to the upper limit value or the lower limit value. The water heater according to claim 1, which has a correction function.