JP3754502B2 - Bath kettle with water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot water bath with a hot water heater using gas, oil, or the like as a fuel, and more particularly, to a hot water bath with a hot water heater capable of more accurately calculating the amount of remaining water.
[0002]
[Prior art]
In a conventional water heater with a water heater, a solenoid valve for bath is connected to a burner for bath, a solenoid valve for hot water is connected to a burner for hot water, and a proportional valve is connected to both solenoid valves. The amount of gas from the original gas solenoid valve is controlled. Thus, by providing a proportional valve having a relatively large capacity in common, it is possible to reduce the cost, and at the same time, it is possible to supply hot water at a desired temperature using the proportional control of the proportional valve. Further, a gas having a constant pressure can be supplied to the bath burner by using the governor function of the proportional valve.
[0003]
On the other hand, in recent years, along with the multi-functionality of a hot water bath with a water heater, one having an automatic hot water function for pouring hot water at a set temperature to a set water level has been sold. In order to realize such a function, it is necessary to detect the amount of water remaining in the bathtub and calculate the remaining amount of water before pouring. In that case, as a method of measuring the water level of the bathtub, that is, the amount of residual water in the bathtub, without using a pressure sensor or the like that leads to an increase in cost, when the temperature of the residual water rises by a predetermined temperature after the bath burner It has been proposed to calculate the amount of heat input by referring to the system efficiency of the bath.
[0004]
Such an arithmetic expression is
Residual water amount (Qz) = (I × Δt) × η / (ΔT × c)
Qz: amount of remaining water (liter) η: system efficiency I: combustion amount (Kcal / h) ΔT: rising temperature (° C.)
Δt: Remembrance time (h) c: Specific heat of water (Kcal / liter · ° C)
I × Δt: input heat amount.
[0005]
Therefore, in the conventional measurement of the residual water amount, either the time (Δt) until the constant temperature (ΔT) rises or the temperature (ΔT) that rises during the constant time (Δt) is measured. It can be done by the method. The system efficiency in the above equation is the ratio of the amount of heat supplied to the hot water with respect to the amount of heat input from the bath burner, usually about 75-80%, but conventionally determined for each product. The value was uniformly stored in the memory of the control unit at the time of factory shipment.
[0006]
[Problems to be solved by the invention]
However, there is a problem that the system efficiency varies due to various factors.
[0007]
FIG. 5 is a chart in which the amount of residual water is calculated for each rise in hot water temperature while performing a chasing operation from a state where there is a predetermined amount of residual water in the bathtub. When calculating using 77% of the system efficiency determined uniformly at the time of factory shipment, it has been found that the amount of residual water differs depending on the end temperature, which is the hot water temperature at the time of calculation. Although this reason is not necessarily clear, it is considered that one of the causes is that the combustion efficiency varies depending on the temperature of the hot water returning to the heat exchanger for bath. The data shown in FIG. 5 is obtained from a state in which a chasing operation for a predetermined time is performed and the heat exchanger and the piping system are sufficiently warmed.
[0008]
In addition, the inventor has also known through experiments that the amount of residual water differs depending on the start temperature of the memory as well as the amount of residual water calculated using a uniform system efficiency. That is, what is empirically found from both data seems to be that the system efficiency varies depending on the temperature of the hot water circulated in the heat exchanger.
[0009]
Secondly, the efficiency of the heat exchanger itself changes due to aging of the heat exchanger, and therefore the system efficiency also differs. In general, it is known that the efficiency decreases as the number of years of use increases.
[0010]
Third, it is also known that the combustion amount I per unit time actually varies even when the gas type is the same and the opening degree of the proportional valve is the same. It is also known that the variation in the amount of combustion depends on, for example, the area where the bath tub is installed and the time zone used.
[0011]
Therefore, there is a limit to accurately calculating the remaining water amount corresponding to the system efficiency that changes from moment to moment only by predicting or learning in advance the system efficiency that changes due to various factors as described above.
[0012]
Therefore, even if the system efficiency changes from moment to moment, the object of the present invention is to calculate the remaining water amount more accurately by obtaining the system efficiency once every time and calculating the remaining water amount using the efficiency. The object is to provide a bath with a hot water heater.
[0013]
[Means for Solving the Problems]
According to the present invention, the above object is to provide a bath heat exchanger, a heat input device for heat for supplying heat to the bath heat exchanger, a hot water supply heat exchanger, and input heat to the hot water heat exchanger. A hot water supply hot water supply means having a hot water supply means connected to a bathtub through a forward pipe and a return pipe,
When the amount of heat is input from the heat amount input means for the bath to raise the temperature of the remaining water in the bathtub, and when calculating the amount of remaining water from the rising temperature of the remaining water, the amount of input heat in between and the system efficiency, the bath heat exchanger Achieved by providing a hot water heater equipped with a control device for calculating the remaining water amount using the system efficiency obtained from the incoming and outgoing temperatures, the circulation flow rate and the amount of heat input Is done.
[0014]
In other words, the efficiency at that time is obtained from the incoming and outgoing temperatures of the bath heat exchanger, the circulation flow rate, and the input heat amount when calculating the residual water amount, and the residual water amount is obtained from the input heat amount and the rising temperature using the efficiency. . By doing so, even if the efficiency fluctuates due to various factors, the calculation can be performed based on the actual efficiency at the time of calculation, so that a more accurate residual water amount can be obtained.
[0015]
For example, after the bath tub has been installed, the control unit performs the reheating operation, and the circulation flow rate is determined based on the incoming and outgoing temperatures of the bath heat exchanger, the amount of heat input, and a predetermined efficiency. Can be requested. Further, a water amount sensor for detecting a circulation flow rate may be provided in a circulation path connecting the bath heat exchanger and the bathtub, and the circulation flow rate detected from the water amount sensor at the time of calculating the remaining water amount may be used.
[0016]
The above object is further achieved in accordance with the present invention, a bath heat exchanger, a heat input means for bath for supplying heat to the bath heat exchanger, a hot water supply heat exchanger, and an input of heat to the hot water heat exchanger. A hot water supply bath with a hot water heater connected to the bathtub via an outward pipe and a return pipe,
When calculating the amount of residual water from the rising temperature of the residual water, the amount of heat input during that time and the system efficiency, the amount of heat is input from the heat input means for the bath to increase the temperature of the residual water in the bathtub. A control device is provided that corrects the system efficiency in accordance with the subsequent temperature difference based on the difference between the incoming water temperature and the outgoing water temperature of the bath heat exchanger and calculates the remaining water amount using the corrected system efficiency. This is achieved by providing a bath with a water heater characterized by the above.
[0017]
In other words, in order to cope with the efficiency that fluctuates dynamically according to the temperature of the hot water circulating during the memorial service, the temperature difference between entering and exiting the heat exchanger is monitored, and the efficiency is corrected according to the temperature difference. A more accurate amount of residual water can be obtained.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to the embodiment.
[0019]
[Overall configuration of the embodiment]
FIG. 1 is an overall configuration diagram of a bath with a hot water heater according to an embodiment of the present invention. The bath boiler 100 with a water heater is provided with a bath combustion chamber 1 and a hot water combustion chamber 2. Each combustion chamber is provided with a bath heat exchanger 10 and a hot water supply heat exchanger 20. Further, the combustion chamber is provided with a bath burner 11 and hot water burner 21 (three ports are provided in FIG. 1), a bath igniter 13 and a hot water igniter 23, a bath frame rod 14 and a hot water frame rod 24 as heat input means. It has been. A common combustion fan 30 is provided for both combustion chambers 1 and 2, and the air burned in each is exhausted through an exhaust port.
[0020]
A bath solenoid valve 12 and a hot water solenoid valve 22 for on / off control of gas supply to the bath burner 11 and the hot water supply burner 21 are provided, and the proportional valve 31 and the original gas solenoid are commonly used for the solenoid valves 12 and 22. A valve 32 is provided. These solenoid valves, proportional valves, igniters, frame rods, combustion fans, various sensors described later, and the like are controlled by a control device such as a microcomputer mounted on the power transmission board 41. The control device is connected to a remote controller 40 in the bathroom or kitchen, receives an operation signal according to a program stored in the memory, and outputs a control signal.
[0021]
The outline of the operation on the water heater side is as follows. First, when the hot water tap is opened, the water amount sensor 25 senses the flow rate of the water supply 28, and after the pre-purge by the combustion fan 30, the main gas solenoid valve 32, the proportional valve 31, and the hot water solenoid valve 22 are opened along with the discharge of the hot water igniter 23. Then, hot water of a predetermined temperature is supplied from the hot water supply port 29. In order to keep the hot water supply temperature at the set temperature, the solenoid valve drive current of the proportional valve 31 is controlled to a value calculated from the outputs of the incoming water thermistor 26, the outgoing hot water thermistor 27 and the water amount sensor 25.
[0022]
On the other hand, on the bath side, by opening the original gas solenoid valve 32, the proportional valve 31, and the bath solenoid valve 12, the bath burner 11 is combusted, and the circulation pump 17 adds water while circulating hot water in the bathtub (not shown).焚 Driving. In the automatic hot water operation, hot water obtained by combustion on the hot water supply side is supplied to the circulation passage on the bath side by opening the hot water solenoid valve 34, and a set amount of hot water is poured into the bathtub. After that, if necessary, the memorial operation is performed up to the set temperature by burning on the bath side. Reference numerals 18 and 19 denote an outward pipe and a return pipe up to the bathtub 43, which are attached to the bathtub by a circulation fitting 44.
[0023]
Also, in the circulation circuit on the bath side, a bathing thermistor 16 for measuring the temperature of hot water entering the heat exchanger 10 and a bath output thermistor 47 for measuring the temperature of hot water exiting from the bath are provided, and for measuring the circulation flow rate. The bath water amount sensor 48 may be further added.
[0024]
FIG. 2 is a block diagram showing the relationship between the control device 45 composed of a microcomputer or the like mounted on the electric board 41 of the bath pot, various sensors, and drive valves. On the electrical board 41, an EEPROM (Electrically Erasable Programmable Read Only Memory) or the like is mounted as a storage device 46 in addition to the control device 45, and storage such as system efficiency is performed.
[0025]
[First embodiment]
In the above-described bath with a water heater, when an automatic hot water operation is instructed from the remote controller, it is first determined whether or not there is residual water in the bathtub 43 beyond the circulation fitting 44. This determination is made based on whether or not the bath water flow switch 15 senses the circulation of the remaining water by operating the circulation pump 17 in the circulation circuit. And when the residual water exceeding the circulation metal fitting 44 is detected, the said residual hot water driving | operation is complete | finished by calculating the residual water amount which is the object of this invention, and pouring to the preset water amount.
[0026]
FIG. 3 is a diagram for explaining a method for obtaining the efficiency η performed every time the remaining water amount is calculated. In order to solve the problem that the efficiency η has conventionally changed due to the circulating hot water temperature, the secular change of the heat exchanger, the gas type, and the like, in this embodiment, as shown in FIG. The efficiency η is calculated every time the residual water amount is calculated from the combustion amount I (Kcal / h) calculated from the opening and the gas type, the circulation flow rate V, and the temperatures Tin and Tout of the bath heat exchanger 10. Ask for. C in the calculation formula in FIG. 3 is the specific heat of water.
[0027]
The circulation flow rate V can be obtained by using the efficiency at the time of factory shipment in the arithmetic expression shown in FIG. 3 during the memorial operation performed after the bath pot is installed. It is preferable to perform this calculation during a learning operation performed immediately after installation. By performing the above calculation after installation, a circulation flow rate V corresponding to the installation environment can be obtained.
[0028]
Then, at the time of the remaining water amount calculation process in the normal operation, an appropriate efficiency η corresponding to a secular change, a gas component change, and the like can be obtained using the circulating flow rate V. Since the circulation flow rate V itself hardly fluctuates depending on the circulating hot water temperature, the secular change of the heat exchanger, the gas component, etc., there is almost no problem by using the circulation flow rate V obtained first.
[0029]
As shown in FIG. 1, when the bath water amount sensor 48 is provided in the circulation path, the circulation flow rate V can be obtained each time the remaining water amount is calculated. In that case, the circulation flow rate V itself can be obtained more accurately.
[0030]
FIG. 4 is a flowchart of the remaining water amount calculation in the case where the bath water amount sensor 48 is not used and the circulation flow rate V is obtained after the bath pot is installed. First, as a preparation, the circulation flow rate V is obtained using the efficiency at the time of shipment from the factory after the bath pot is installed (step S1). Then, when the remaining water calculation such as automatic hot water operation starts during the subsequent normal operation (step S2), combustion of the bath burner 11 is started (step S3).
[0031]
In this flowchart, the amount of remaining water is calculated every time the bath temperature rises once (or one digit in the microcomputer). When the bath temperature rises by 1 degree (or 1 digit) (step S4), the bathing heat exchanger 10 entrance and exit temperatures Tin and Tout are detected by the bathing thermistor 16 and the bathing thermistor 47, respectively, as shown in FIG. The efficiency η at that time is obtained according to the equation shown in (5). At this time, if the efficiency η is significantly different from the existing value, there is a high possibility that it is due to other factors other than the circulating hot water temperature, aging, and gas components. In that case, the existing efficiency η is used. The remaining water amount is calculated (steps S6 and S8). Another possible cause is when, for example, the circulating metal fitting 44 is blocked by a human body taking a bath and the circulating flow rate is greatly reduced from the calculated value V. The degree of change in which the change in efficiency is ignored is appropriately set based on empirical rules.
[0032]
Further, when the calculated value of efficiency η is within a predetermined allowable range from the existing value, if the calculated value of efficiency η is different from the existing value, the remaining water amount is calculated using the calculated value ( Step S9). If there is no change, the remaining water amount is calculated with the efficiency of the existing value (step S8).
[0033]
The above steps are repeated until the bathtub rises to a predetermined temperature (step S10), and when the temperature rises to that temperature, the remaining water calculation process ends.
[0034]
Several modifications can be considered for the remaining water calculation step. First, when the bath water amount sensor 48 is provided, the circulation flow rate V is obtained from the detected flow rate from the bath water amount sensor when the efficiency η is obtained in step S5. Accordingly, the step S1 is omitted. Second, step S4 can be omitted, and the remaining water amount calculation in steps S5 to S9 can be performed after the bath temperature has simply risen to a predetermined temperature. Similarly, step S4 can be omitted, and the remaining water amount calculation in steps S5 to S9 can be performed after a predetermined time has elapsed.
[0035]
Third, for example, in order to cope with the case where the amount of combustion I changes dynamically due to a change in the opening of the proportional valve due to the operation on the water heater side, for example, the frequency is higher than the frequency of 1 digit increase in step S4 ( It is also possible to obtain an integral value of the combustion amount (with a short sampling time). In that case, when the bath water amount sensor 48 is used, the integral value of the combustion amount can be obtained after obtaining the efficiency η for each sampling time.
[0036]
[Second Embodiment]
As described with reference to the data in FIG. 5, it can be seen that the efficiency is clearly changed immediately after the start of the chasing operation for calculating the remaining water amount and after the circulating hot water temperature rises. In this way, in order to more easily obtain the efficiency that changes rapidly during the memorial service, in the second embodiment, the bath heat exchanger 10 is simply turned on and off based on the efficiency at the start of the memorial service. The efficiency is corrected in accordance with the change in the difference between the temperatures Tin and Tout.
[0037]
Specifically, the efficiency η at the start of the remedy is set to be the same as that of the first embodiment by using the circulation flow rate V obtained when the bath tub is installed or obtained from the bath water amount sensor 48 at the start of the remedy. Ask. As a result, it is possible to absorb variations due to aging of the heat exchanger and gas components. Next, with reference to the efficiency η, the difference (Tout−Tin) between the hot water temperature of the bath heat exchanger 10 and the hot water temperature, which changes during the memory when calculating the remaining water amount, is monitored. If the difference in hot water temperature changes, the corresponding correction is applied to the reference efficiency η. As is clear from the data shown in FIG. 5, the actual efficiency decreases as the circulating hot water temperature rises. This is because if the efficiency is calculated with a constant value, the amount of residual water that should be a constant value increases. Therefore, the temperature difference between entering and exiting the bath heat exchanger 10 decreases as the hot water temperature rises. This change is detected and the efficiency is corrected. Therefore, the calculation formula of the remaining water amount is as follows.
[0038]
Residual water amount (Qz) = (I × Δt) × η × ηa / (ΔT × c)
Qz: Residual water amount (liter) η: System efficiency I: Combustion amount (Kcal / h) ηa: Efficiency correction value Δt: Remembrance time (h) ΔT: Increased temperature (° C.)
I × Δt: Input heat amount c: Specific heat of water (Kcal / liter · ° C)
Therefore, in step S5 in the flowchart shown in FIG. 4, the second embodiment can be realized only by obtaining the efficiency correction value ηa from the hot and cold hot water temperatures Tin and Tout of the bath heat exchanger 10. .
[0039]
【The invention's effect】
As described above, according to the present invention, the system efficiency can be obtained from the actual measurement value every time the remaining water amount is calculated. Therefore, the residual water amount can be calculated according to the efficiency including all the factors without dealing with various factors that cause the system efficiency η to vary. Therefore, more accurate calculation of the remaining water amount can be performed, and hot water filling to an accurate set water amount can be realized in the automatic hot water beam operation.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a bath with a hot water heater according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the relationship between a control device composed of a microcomputer or the like mounted on an electric board of a bath pot, various sensors, and a drive valve.
FIG. 3 is a diagram for explaining a method for obtaining efficiency η each time a residual water amount is calculated.
FIG. 4 is a flowchart of residual water amount calculation.
FIG. 5 is a chart in which the amount of remaining water is calculated for each rise in hot water temperature while performing a chasing operation from a state where there is a predetermined amount of remaining water in the bathtub.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Bath heat exchanger 11 Bath burner 16 Bath thermistor 17 Circulation pump 47 Bath exit thermistor 48 Bath water quantity sensor 20 Hot water heat exchanger 21 Hot water burner 31 Proportional valve 43 Bath 45 Control device

Claims (1)

A bath heat exchanger, a bath heat amount input means for supplying heat to the bath heat exchanger, a hot water supply heat exchanger, and a hot water supply heat input device for supplying heat to the hot water heat exchanger. A bath with a water heater connected to the bathtub via a pipe and a return pipe,
After the bath has been installed, a memorial operation is performed to determine the circulation flow rate in the memorial operation from the incoming and outgoing temperatures of the bath heat exchanger, the amount of heat input, and the initial system efficiency at the time of shipment from the factory. , The amount of heat from the bath heat amount input means is increased to increase the temperature of the remaining water in the bathtub, and the bath heat exchange is performed when calculating the amount of remaining water from the rising temperature of the remaining water, the amount of input heat in between and the system efficiency. A bath with a hot water heater provided with a control device for calculating the remaining water amount using the new system efficiency obtained from the incoming and outgoing temperatures of the water heater, the obtained circulation flow rate, and the amount of heat input Kettle.

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