JPH0933107A - Measuring method for remaining amount of bath water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly measure a remaining amount of bath water in a bathtub by a method wherein the flow rate of circulation in a circulating passage is detected to correct the flow rate of circulation so as to increase the remaining amount of bath water when the flow rate of circulation is small. SOLUTION: Bath water 11 in a heat exchanger 3 for heating the bath water 11 of a bathtub 1 and the bathtub 1 is circulated by a circulation pump 14 through a circulating passage 8 while the remaining amount of bath water in the bathtub 1 is obtained from the increasing speed of a bath water temperature, detected by a temperature sensor 41 provided in the circulating passage 8 so as to be positioned at the upstream side of the heat exchanger 3, and the amount of heat transmitted to the bath water 11 through the heat exchanger 3 to supplement hot-water from a hot-water filling mechanism 6 into the bathtub 1. In this case, the flow rate of circulation in the circulating passage 8 is detected to correct the remaining amount of bath water so as to be increased when the flow rate of circulation is small. According to this method, the remaining amount of bath water in the bathtub 1 can be measured correctly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the remaining amount of hot and cold water in a bathtub, which is used in a heating circulation system such as a bath water heater having a function of automatically filling the bathtub with water up to a set water level.

[0002]

2. Description of the Related Art When a bathtub is automatically filled with water to a set water level, if hot water remains in the bathtub, a difference in volume of hot water from the specified volume of the bathtub will be supplied to the bathtub. There is a need to. By the way, the bath water heater is configured to circulate hot water in the bathtub through a heat exchanger using a circulation pump to heat the water. In this case, if the amount of heat transferred to the hot water through the heat exchanger is constant, the hot water temperature rises faster as the hot water residual amount decreases. Therefore, the amount of remaining hot water can be known from the correlation between the amount of heat transferred to the hot water and the rising speed of the temperature of the hot water in the bathtub. Therefore, conventionally, the amount of heat transferred to the circulating hot water is obtained from the heat generation amount of the heat source and the efficiency of the heat exchanger, and the rising speed of the hot and cold water temperature in the bathtub is set to the temperature provided in the circulation path on the upstream side of the heat exchanger. The amount of hot and cold water remaining is detected by the sensor.

[0003]

When the amount of hot water remaining is determined by the above-mentioned conventional method, when the hot water that has passed through the heat exchanger and returns to the bathtub, it is completely mixed with the hot water in the bathtub and the whole is mixed. It is assumed that a part of the uniform temperature is recirculated to the heat exchanger. However, in reality, the suction port, which is the upstream end of the circulation path, and the discharge port, which is the downstream end, are often provided at positions relatively close to each other on the inner wall of the bathtub. When and are arranged close to each other, even if the hot water heated through the heat exchanger is discharged into the bathtub from the discharge port, it is sucked into the circulation path from the suction port before being completely mixed with the hot water in the bathtub, A so-called short circuit phenomenon occurs. On the other hand, the temperature of the hot water is detected by a temperature sensor provided in the circulation path upstream of the heat exchanger. When such a short circuit occurs, the temperature sensor detects a temperature higher than that of the hot water in the bathtub, There is a tendency to measure the remaining amount of hot and cold water inside the actual amount of hot water and water less than the actual amount. If hot water is supplied based on the measured remaining hot water amount less than the actual remaining hot water amount, the hot water supply amount becomes unnecessarily large and the hot water overflows from the bathtub.

In view of the above problems, it is an object of the present invention to provide a method capable of accurately measuring the amount of hot water remaining in a bathtub.

[0005]

In order to achieve the above object, the present invention provides a heating circulation including a heat exchanger for heating hot and cold water in a bathtub through a circulation path and a circulation pump for circulating hot and cold water in the bathtub. Used in the system, the rate of rise of the hot and cold water temperature detected by the temperature sensor installed in the circulation path located upstream of the heat exchanger and the amount of heat transferred to the hot water through the heat exchanger cause In the method of determining the amount of hot water remaining,
It is characterized in that the circulation flow rate of the circulation path is detected, and the smaller the circulation flow rate, the larger the amount of hot water remaining is corrected.

When piping is actually carried out, the pipe resistance and the circulating flow rate may differ due to the difference in each working condition. If the inner diameter of the circulation path is the same, the circulation flow velocity becomes slower as the circulation flow rate in the circulation path decreases. When the circulation flow velocity is slow, the rate of discharge of hot water heated through the heat exchanger into the bathtub from the discharge port slows down, so the heated hot water is not sufficiently diffused in the bathtub and circulates. Remains near the outlet of the passage. On the other hand, since the suction port of the circulation path is provided near the discharge port as described above, the amount of hot water that short-circuits from the discharge port of the circulation path to the suction port without diffusion into the bathtub increases. Therefore, as the flow rate in the circulation path decreases, the amount of hot water that short-circuits increases, the temperature rise speed of the hot water detected by the temperature sensor becomes faster, and it is determined that the hot water residual amount is less than the actual hot water residual amount. Therefore, the flow rate in the circulation path is detected, and the smaller the flow rate, the higher the measured hot water remaining amount is corrected so that the measured hot water residual amount approaches the actual hot water residual amount.

Although a flow meter using a movable part such as an impeller may be provided in the circulation path to detect the circulation flow rate, foreign matter such as dust and hair is contained in the hot and cold water in the bathtub. Since it is often mixed in, the flow meter may get stuck on the moving part and fail. By the way, if the amount of heat transferred to the hot water via the heat exchanger is constant, the smaller the circulation flow rate, the larger the temperature difference between the hot water temperature on the upstream side and the hot water temperature on the downstream side of the heat exchanger. Therefore, the circulation flow rate is determined from the temperature difference and the heat quantity without providing a flow meter in the circulation path.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION 1 is a bathtub, and hot water 11
have. The hot and cold water 11 is heated by the burner 2 which is a heat source. The water circulated by the heat medium pump 31 is used as a heat medium, and the heat medium is heated by the gas-liquid type heat exchanger 21, and the liquid-liquid To the mold heat exchanger 3. On the other hand, the hot water 11 in the bathtub 1 is configured to circulate in the heat exchanger 3 by the circulation pump 4. Then, the inlet temperature and the outlet temperature of the hot water 11 circulated in the heat exchanger 3 are detected by the temperature sensors 41 and 42, respectively. By the way, the heat medium is supplied to the heat exchanger 3 and the hot water 11 in the bathtub 1
Not only is it heated, but it is also branched into the hot water mat 5 for floor heating in the middle of the circulation path 8 and used for indoor heating.
On / off of heating by the hot water mat 5 is performed by the open / close valve 51. When the open / close valve 51 is opened, the heating medium is supplied to the hot water mat 5 to perform indoor heating, and when the open / close valve 51 is closed, the hot water mat 5 is opened. Supply of the heat medium to 5 is prohibited, and all the heat medium is supplied to the heat exchanger 3. A water filling mechanism 6 is connected between the temperature sensor 42 and the bathtub 1 via an opening / closing valve 61. When the opening / closing valve 61 is opened, the hot water heated by the water filling mechanism 6 is supplied to the bathtub 1. The bathtub 1 is automatically filled with water.

In the above structure, when automatically filling water using the water filling mechanism 6, the hot water filling mechanism 6 determines how much water to add to the bathtub 1, so You need to know how much 11 is left.

The amount of heat transferred to the hot and cold water 11 via the heat exchanger 3 is Q (Kcal / min), and the rate of temperature rise of the hot and cold water 11 in the bathtub detected by the temperature sensor 41 is Vt.
(C / min), the remaining amount W (l (liter)) of the hot water 11 is expressed by Q = W · Vt, W = Q / Vt (1) Since the temperature of the hot water in the bathtub 1 is detected by the temperature sensor 41 provided on the upstream side of the heat exchanger 3 as described above, the temperature sensor may not be provided in the bathtub 1.

However, the circulation flow rate M by the circulation pump 4 is easily affected by the piping resistance and the like, and even if the same pump is used, the circulation flow rate M may differ depending on the piping state. Since the pipe diameters of the circulation paths are the same, if the circulation flow rate M is different, the circulation flow velocity is also different. That is, when the piping resistance is small and the circulation flow rate M is large, the circulation flow rate is fast, and when the piping resistance is large and the circulation flow rate M is small, the circulation flow rate is slow. On the other hand, hot water 1 in the bathtub 1
The suction port 71 for sucking 1 into the circulation path and the discharge port 72 for discharging from the circulation path into the bath 1 are provided relatively close to each other. The rate at which the hot water discharged inside is sucked into the suction port 71 before it diffuses into the bathtub 1 increases. Then, the temperature detected by the temperature sensor 41 becomes higher than the actual temperature of the hot water 11 in the bathtub 1. Therefore, the temperature rising speed Vt increases, and the remaining amount W is calculated to be smaller than the actual remaining amount from the above equation (1). If hot water filling is performed based on the calculation result, an unnecessarily large amount of hot water is added, and hot water 11 may overflow from the bathtub 1.

The so-called short circuit in which the hot water discharged from the discharge port 72 is sucked into the suction port 71 before diffusing into the bathtub 1 increases as the discharge speed of the hot water from the discharge port 72 decreases. Therefore, the circulating flow rate may be detected and the remaining amount W calculated by the equation (1) may be corrected based on the circulating flow rate. Although a circulating meter may be provided in the circulation path of the hot water 11 to detect the circulating flow rate, foreign matter such as dust or hair is often mixed in the hot water 11 in the bathtub 1, so that the flow rate is There are cases in which the meter does not work. Therefore, for example, in the state where the heating operation is not performed as in the case of the bath additional heating operation, the temperature difference Δ detected by the temperature sensors 41 and 42 is Δ.
The circulating flow rate q (l / min) is calculated based on t (° C.) by the following equation (2) and stored in a storage means such as an EEPROM (erasable electrically rewritable read-only memory). However, c is a specific heat (Kcal / l.degree. C.).
The circulating flow rate q is obtained in the state where the heating operation is not performed. When the heat medium flows to the hot water mat 5, the amount of heat transferred to the hot water 11 via the heat exchanger 3 fluctuates. Because you cannot ask for.

Q = Q / (Δt · c) (2) Then, the correction coefficient K is obtained based on the circulation flow rate q, and the correction coefficient K is corrected by multiplying the remaining amount W. For example, as shown in FIG. 2, the correction coefficient K has a maximum value (1.54) when the circulation flow rate q is the minimum value (3 (l / min)), and decreases as the circulation flow rate q increases. However, when the predetermined circulation flow rate (12 (l / min)) is exceeded, K = 1 is set so that the correction is not substantially performed. The relationship between the circulation flow rate q and the correction coefficient K shown in FIG. 2 is the suction port 71 and the discharge port 72.
It is determined by the positional relationship and shape with respect to, or the size of the bathtub 11, etc., and the value shown in FIG. It may be set so as to decrease in a curve that gradually approaches = 1.

When the heating operation and the bath heating operation are performed at the same time, the heat quantity Q transferred to the hot water 11 via the heat exchanger 3 is the difference Δ in temperature detected by the temperature sensors 41 and 42.
It is calculated based on t and the circulation flow rate q. In this case, the correction of the remaining hot water amount may be performed by multiplying the correction coefficient K by the remaining amount W, but may be calculated by correcting the circulation flow rate q so that the remaining hot water amount is corrected. Further, in the above embodiment, the liquid-
Although the one in which hot water is heated through the heat medium using the liquid heat exchanger 3 is shown, the hot water is directly heated by the heat source without using the heat medium by using the gas-liquid heat exchanger. You can

By the way, in the above embodiment, the burner is used as the heat source, but other things such as an electric heater may be used as the heat source.

[0016]

As is apparent from the above description, according to the present invention, even if the flow rate circulated to the heat exchanger through the circulation path is increased or decreased depending on the piping condition or the like, the amount of hot water remaining in the bathtub can be accurately determined. Can be measured.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a circulation flow rate q and a correction coefficient K.

[Explanation of symbols]

 1 Bathtub 2 Burner 3 Heat Exchanger (Liquid-Liquid Type) 4 Circulation Pump 5 Hot Water Mat 6 Hot Water Filling Mechanism 11 Hot Water 41 Temperature Sensor 42 Temperature Sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Yamada 2-26 Fukuzumi-cho, Nakagawa-ku, Nagoya, Aichi Prefecture

Claims (2)

[Claims] 1. A heating and circulating system comprising a heat exchanger for heating hot and cold water in a bathtub through a circulation path and a circulation pump for circulating hot and cold water in the bathtub so that it is located upstream of the heat exchanger. In the method of determining the amount of hot and cold water in the bath from the rate of rise of the hot and cold water temperature detected by the temperature sensor provided in the circulation path and the amount of heat transferred to the hot water through the heat exchanger, the circulation flow rate of the circulation path is A method for measuring the remaining amount of hot and cold water, which comprises detecting and performing a correction to increase the remaining amount of hot and cold water as the circulating flow rate decreases. 2. The circulating flow rate is obtained from the temperature difference between the temperature of the hot water and the temperature of the hot water at the downstream of the heat exchanger, and the amount of heat transferred to the hot water via the heat exchanger. The hot water remaining amount measuring method according to claim 1.