JP2894590B2 - Temperature control device for hot and cold water in bathtub - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for hot water in a bath tub, which supplies hot water to a bath tub by heating it with a heat exchanger and circulates the hot water in the bath tub through the heat exchanger to heat the hot water.

[0002]

2. Description of the Related Art Conventionally, as a bath apparatus for heating and circulating hot and cold water in a bath tub through a heat exchanger and performing reheating control for controlling the temperature in the bath tub, Japanese Utility Model No. 2-9333, "Forced circulation type bath pot" There is an automatic temperature controller. This device heats and circulates water and hot water in a bathtub through a heat exchanger between a bathtub and a heat exchanger through a circulation pipe, and detects the temperature detected by a temperature detector installed in the circulation pipe and the temperature setting installed in the bathroom etc. This is a forced circulation bath kettle that controls the operation of the pump and the combustion of the burner by comparing the temperature with a set temperature set by a heater. The temperature control device for the forced circulation bath kettle performs the following temperature control operation.

A. After reaching the set temperature, the pump is operated after a certain period of time. b. After a predetermined time has elapsed after the operation of the pump, the temperature detected by the temperature detector is compared with the set temperature. c. When the detected temperature is lower than the allowable temperature of the set temperature, the pump is continuously operated and the burner is burned. d. If the detected temperature is within the allowable temperature of the set temperature, the operation of the pump is stopped. e. When the operation of the pump is stopped, a certain time (same as the certain time in the case of a) after the stop of the pump operation
After the operation of the pump after the elapse of the period, the processes of b to d are performed.

[0004]

By the way, in this temperature control device, the allowable temperature (-Δ
When T) is set, the start of additional heating is delayed depending on the setting range of the allowable temperature, and as a result, there is an inconvenience that the time to reach the set temperature becomes longer. For example, set temperature 4
The allowable temperature is set to ΔT = 1 ° C. for 0 ° C. In this case, if the detected temperature is 39.1 ° C. after a lapse of a certain time (t1), the temperature drop is 0.9 ° C., which is within the allowable temperature range (ΔT> 0.9). Ignition is forgotten and the pump operation is stopped. Then, after a lapse of a predetermined time (t2) from the stop of the pump, the pump is operated, and it is determined whether or not the detected temperature after a lapse of a predetermined time (t3) from the start of the operation of the pump is within an allowable temperature range. After the temperature reached the set temperature, the temperature dropped by 0.9 ° C. at a certain time t1, and it is expected that the temperature dropped to about 37 ° C. at a time t2 + t3. In order to raise the temperature from the temperature drop to the set temperature, additional heating time is required in proportion to the amount of hot water in the bathtub. The fact that the temperature drop at the time of the first temperature detection is slightly higher by 0.1 ° C. rather takes a longer time to start additional heating and additional heating time, which gives a bather discomfort.

[0005] In this case, once the pump stops, a time t2 from the stop of the pump operation to the start of the pump operation.
Is added to the pump operation time t3, and the time from the stoppage of the pump operation to the ignition of the burner becomes (t2 + t3). Since this time is considerably long, the time interval from the completion of the additional heating to the start of the next additional heating becomes longer. is there.

Setting a specific allowable temperature on the basis of an absolute set temperature as described above is effective in preventing the inconvenience of frequently repeating ignition and extinguishing of a burner. Setting the allowable temperature with respect to the set temperature requires a certain degree of accuracy in the value of the set temperature and the temperature range of the allowable temperature, and the accuracy affects temperature control. Such a control that requires accuracy in the set temperature and the allowable temperature has the advantage that the repeated ignition and extinguishing of the burner, that is, the advantage of preventing the chattering phenomenon, cannot be ignored, but the feasibility is at the laboratory stage. ,
As an actual bath apparatus, irregularities in characteristics cause poor reliability, and the inconvenience that equipment costs are high cannot be ignored.

Therefore, the present invention provides a temperature control device for hot and cold water in a bath tub which realizes temperature control that can reach the set temperature as quickly as possible by simplifying the comparison process between the set temperature and the detected temperature. The purpose is to:

[0008]

As shown in FIG. 1, the temperature control apparatus for hot and cold water in a bathtub according to the present invention includes a bathtub (12) and a heat exchanger (heat exchanger 18 for additional heating). (The bathtub going pipe 8 and the bathtub return pipe 10) are connected to each other, and the hot water in the bathtub is circulated to the heat exchanger by a circulation pump (28) provided in a circulation path and heated to control the temperature to the set temperature. A temperature control device for controlling the temperature of hot water in a bath tub, wherein the burner heats the heat exchanger by burning supplied fuel gas (burner for additional heating 50), and a control valve for switching the supply of the combustion gas to the burner. (A gas opening / closing valve 52 for additional heating), a temperature sensor (32) provided in the circulation path for detecting the temperature of the hot water, and stopping the combustion of the burner when the hot water in the bath tub reaches a set temperature. After a certain period of time, Both start circulating the circulating the hot water in said bathtub to the circulation path by operating the ring pump
Sometimes the temperature of the hot or cold water that has stayed in the circulation
The temperature is detected by a sensor and compared with the set temperature.
If the temperature is lower than the set temperature, open the control valve and
The burner performs a burning operation, and the detected temperature is set to the set value.
If the temperature is equal to or higher than the temperature, the circulation of the hot water is continued for a predetermined time.
After that, the temperature of the hot and cold water in the bathtub is lower than the set temperature.
The combustion operation of the burner is performed.
The temperature sensor detects a rise in the temperature of the hot and cold water circulating in the circulation path during the combustion operation, and measures a time during which the detected temperature is continuously higher than the set temperature. A control means (control section 60) for performing heat retention control for closing the control valve at the time of exceeding the temperature and stopping the combustion operation of the burner is provided.

In the apparatus for controlling the temperature of hot and cold water in a bathtub according to the present invention, the control means controls the temperature of the hot water during a combustion operation of the burner.
Whether the temperature detected by the temperature sensor has exceeded the set temperature
Time measurement starts, and the detected temperature
When the temperature becomes lower than the set temperature, the measurement time is reset.
The detected temperature is continuously set by the
It is characterized by measuring the time when the temperature becomes higher than the temperature .

In the temperature control apparatus for hot and cold water in a bathtub according to the present invention, the processing of the control means is performed by digital processing by converting the set temperature and the detected temperature into digital data in addition to analog processing.

In the temperature control apparatus for hot and cold water in a bathtub according to the present invention, the set temperature has a temperature width equivalent to the resolution in units of a resolution of an analog / digital converter (72) for digitally converting the detected temperature. It is characterized by the following.

Further, in the temperature control device for hot and cold water in a bathtub according to the present invention, the analog /
A temperature width equal to or exceeding the resolution of the digital converter is set.

[0013]

According to the temperature control device for hot water in the bath tub of the present invention, after the hot water in the bath tub reaches the set temperature, the circulation pump is operated after a certain period of time to circulate the hot water in the bath tub through the circulation path. . The reason why the operation of the circulation pump is started for a certain time after the set temperature is reached is that the temperature of the hot water that has reached the set temperature is maintained at the same temperature as the set temperature before the certain time has elapsed. And after a certain period of time,
When the circulation pump is driven, the hot water in the bathtub circulates in the circulation path, and as a result, the hot water in the bathtub is stirred, and the temperature difference between the hot water in the circulation path and the hot water in the bathtub is eliminated. Therefore, after a lapse of a predetermined time from the start of the operation of the circulation pump, the detected temperature of the temperature sensor is compared with the set temperature.
As a result of this comparison, if the detected temperature is lower than the set temperature, a warming operation is performed. This warming operation continues until the detected temperature reaches the set temperature.

In the temperature control apparatus for hot and cold water in the bathtub, the heat retention operation is performed by continuing the operation of the circulation pump, igniting the burner, and starting additional heating. The reheating reaches the hot water of the detected temperature is a set temperature in the bathtub, the
Time measurement is performed from the time of arrival, and the detected temperature is continuously
The process is performed until the time when the temperature becomes equal to or higher than the set temperature continues for a predetermined time.
As a result, the temperature of hot and cold water in the bathtub is always maintained at or above the set temperature.
Can be warmed.

In the temperature control apparatus for hot and cold water in a bathtub according to the present invention, the control means converts the set temperature and the detected temperature into digital data using analog / digital conversion means in addition to analog processing. Digital processing can be easily performed by a microcomputer or the like, and the reliability of operation can be improved.

The set temperature can be set arbitrarily.
By setting the resolution of the analog-to-digital converter that converts the detected temperature to digital as a unit and setting the temperature width equal to the resolution, the temperature comparison process becomes easier, the accuracy becomes higher, and the temperature becomes more reliable. Control can be realized. As a result, such processing also contributes to safety.

In the temperature control apparatus for hot and cold water in a bathtub according to the present invention, the interval between the set temperatures which is set stepwise greatly affects the temperature control. This temperature range can be set arbitrarily, but if it is set to a large value, the set temperature value, which is the target value, is limited. Therefore, in the present invention, a temperature width equal to or exceeding the resolution of the analog-digital converter is set. For example, assuming that the set temperature is set in units of 1 ° C., the width of the set temperature is set to the resolution of the analog / digital converter. Assuming that the resolution is 0.5 ° C., the set temperature and the interval temperature are set alternately in steps of 0.5 ° C. That is, the resolution of the analog-to-digital converter is used as a unit, the temperature interval of 0.5 ° C. is used as the temperature interval, and 0.5
There is a set temperature with a temperature range of ° C. The detected temperature is set to analog /
When compared by digital conversion, it is possible to easily and accurately judge whether they match or not, and the trouble of setting the allowable temperature for the absolute set temperature and the necessary accuracy setting as in the past Is unnecessary, and temperature control suitable for human temperature sensation can be realized.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings.

FIGS. 1, 2 and 3 show an embodiment of the temperature control device for hot and cold water in a bathtub according to the present invention. This temperature control device for hot and cold water in a bathtub is constituted by a hot water supply / reheating device 2 used for a bath or the like. The hot water supply / reheating unit 2 includes a hot water supply circuit 4 and a reheating unit 6 and is connected to a circulation port 14 of a bathtub 12 serving as a container for storing hot water through a bathtub going pipe 8 and a bathtub return pipe 10. ing. Hot water is supplied to the bathtub 12 through a bathtub going pipe 8 which forms a part of the hot water supply circuit 4 at the time of hot water supply. The additional heating of the hot water HW in the bathtub 12 is performed.

In this embodiment, the hot water supply / reheating unit 2 is provided with a heat exchanger 16 for hot water supply as a first heating source and a heat exchanger 18 for additional heating as a second heating source. I have. The reason why the two heat exchangers 16 and 18 are installed in this way is that the heating of the feed water W from the water supply side and the sewage side, that is, the bathtub 1
This is because the heating of the hot and cold water HW in 2 is separated and the heating is performed independently.

The hot water supply circuit 4 is provided with the bathtub 1 from the water supply side.
2 is a circuit for supplying hot water. That is, the water supply W from the water supply system such as a water supply is supplied to the pipeline 20.
0 is supplied to the hot water supply heat exchanger 16. The hot water obtained in the hot water supply heat exchanger 16 passes through an open / close solenoid valve 22 to reach a pressure feed hopper 24 which is a means for separating from the sewage. The hot water supplied to the pressure feed hopper 24 is supplied to a first switching valve 26.
Then, the water reaches the bathtub going pipe 8 and is supplied to the bathtub 12.

The reheating circuit 6 is a circuit for reheating the hot water HW in the bathtub 12 to keep it warm, and is an open-to-atmosphere closed circuit formed between the bathtub 12 and the heat exchanger 18 for reheating. And a circulation pump 28 is provided as a pressurizing means for circulating the hot and cold water. By the operation of the circulation pump 28, the hot and cold water flowing from the bathtub 12 to the bathtub return pipe 10 passes through the second switching valve 30 and is supplied to the reheating heat exchanger 1.
8, the hot water heated by the reheating heat exchanger 18 passes through the switching valve 26 and passes through the bathtub going pipe 8 to the bathtub 12.
Leads to. The bathtub return pipe 10 forming a circulation path is provided with a temperature sensor 32 as a means for detecting the temperature of hot water in the bathtub 12 through circulating flowing water, and a water level sensor 34 as a means for detecting a water level in the bathtub 12. . The water level sensor 34 is composed of, for example, a pressure sensor. In addition, a flowing water switch 38 is installed in a pipe 36 connecting the circulating pump 28 and the additional heat exchanger 18 as means for electrically detecting the presence or absence of circulating flowing water.

A hot water supply burner 40 is installed as a heat source on the hot water supply heat exchanger 16 side, and gas G as fuel is supplied to the hot water supply burner 40 via a hot water supply gas proportional valve 42 as a control valve. Supplied. The hot water supply burner 40 is provided with a hot water supply frame rod 44 and a hot water supply igniter 46.

A reheating burner 50 is installed on the side of the reheating heat exchanger 18 as a heat source, and the reburning burner 50 is used as a control valve as a fuel via a reheating gas opening / closing valve 52. Is supplied independently of the hot water supply burner 40. In addition, the reburning burner 50
Additional firing frame rod 54 and additional igniter 5
6 are installed.

Next, FIG. 2 shows a control circuit of the hot water supply / reheating unit 2. This control circuit is control means for performing heat retention control together with hot water supply control, and a microcomputer is used for the control unit 60. The control unit 60 includes a central processing unit (CPU) 62, a ROM 64 as a storage unit, a RAM 66, and an EEPROM 68. Various control programs such as hot water supply and additional heating are stored in the ROM 64, data in the course of calculation and detection data are stored in the RAM 66, and an EEPROM
Reference numeral 68 stores fixed data obtained during the control, and the data is updated as needed.

The control unit 60 receives detection signals from the temperature sensor 32 and the water level sensor 34, and a multiplexer 70 is provided as a means for capturing these detection signals in a time-division manner.
A control signal is provided from U62. Further, since these detection signals are analog signals, an analog / digital converter (A / D) 72 is provided as means for converting into digital signals in order to perform digital processing.
That is, the temperature detection signal and the water level detection signal are taken in at regular time intervals, converted into digital signals, and applied to the CPU 62 as digital data.

The control unit 60 is provided with an input / output circuit 74 for taking in signals from various sensors and the like and applying control output to various drive circuits. Output signals of the running water switch 38, the hot water supply frame rod 44, and the additional heating frame rod 54 are applied to the input / output circuit 74.

The control output of the control section 60 is output through an input / output circuit 74, and each control output is provided by an opening / closing solenoid valve driving circuit 76, a pump driving circuit 78, and switching valve driving circuits 80 and 8,
2. Gas proportional valve drive circuit 84, gas open / close valve drive circuit 8
6, added to the igniter drive circuits 88 and 90. As a result, the opening / closing solenoid valve 22 has an opening / closing solenoid valve driving circuit 76, the circulating pump 28 has a pump driving circuit 78, the switching valves 26 and 30 have switching valve driving circuits 80 and 82, and the gas proportional valve 42 has a gas A drive output is supplied to the proportional valve drive circuit 84, the gas open / close valve 52 to the gas open / close valve drive circuit 86, the hot water supply igniter 46 to the igniter drive circuit 88, and the additional heating igniter 56 to the igniter drive circuit 90.

In this control circuit, a remote controller 92 is provided as a remote controller for the controller 60. A remote controller 94 is connected to the input / output circuit 74 of the controller 60. The remote controller 94 includes a remote controller input unit 96, an audio output unit 98, and a display unit 1.
00 is connected. A water level setting input is given to the remote control input section 96 together with the temperature setting input. The temperature can be set by the user at any temperature, for example, 42 ° C., 4 ° C.
It is set in units of 1 ° C, such as 3 ° C. The set temperature is displayed on the display unit 100 as a numerical value and its unit, and is stored in the RAM 66 as digital data D42 and D43 representing target values.

Next, FIG. 3 shows a specific configuration example of the temperature sensor 32 and the AD converter. A thermistor 102 as a temperature detecting element is used for the temperature sensor 32. A reference resistor 104 is connected in series to the thermistor 102. In these series circuits, the resistor 104 is connected to the power supply and the thermistor 102 is connected to the ground. A reference voltage Vdd is applied. Then, a connection point between the resistor 104 and the thermistor 102 is set as the temperature detection output point P, and the output point P
Has a thermistor 102 whose resistance value changes with temperature.
, That is, a temperature detection output is obtained. This detection output passes through the multiplexer 70 and is applied to the sample and hold circuit 106.

The sample and hold circuit 106 is a means for sampling and holding a constantly changing detection output in accordance with a constant timing signal from the CPU 62, that is, a sampling pulse SP. This sample timing is synchronized with the temperature detection timing on the CPU 62 side. In this embodiment, for the sake of simplicity, the sample and hold circuit 106 is equivalently shown, and the switch 108 is opened and closed by the sampling pulse SP.
During the closing time, the detection output that is the current value is held in the capacitor 110. That is, the holding voltage VH indicates the current detected temperature. This holding voltage VH is analog data,
It is applied to a voltage comparator 112 for digitization.

The voltage comparator 112 converts the detected output into digital data of several bits by comparing the detected output with reference voltages V1, V2,..., Vn. A reference voltage setting circuit 114 is provided as a means for setting the reference voltages V1, V2,..., Vn. In this embodiment, the reference voltage Vdd is divided into n by the resistance ratio of the voltage dividing resistor 116, and Vm is used as a unit. Step voltage reference voltage V
0, V1, V2... Vn (= Vdd) are obtained. This division unit is the resolution of the analog / digital conversion.

In this embodiment, the reference voltages V0, V
1, V2,..., Vn are voltages that set Vm to several tens of millivolts and step by 0.5 ° C. in temperature conversion. Here, the step of 0.5 ° C. means, for example, that the temperature range of 39 ± 0.25 ° C. is V39, 40 ± 0.
The temperature range of 25 ° C. is set to V40..., And the voltage corresponding to the temperature as the absolute value is not set.

The reference voltage setting circuit 11
Tap selector 118 as selection means for selectively extracting reference voltages V0, V1, V2,.
Is provided. The tap selector 118 includes C
A tap select pulse TS is applied from the PU 62, and the tap select pulse TS causes each of the reference voltages V0,
Vn, V2,..., Vn are cyclically selected and output.

The voltage comparator 112 sequentially compares the reference voltages V0, V1, V2,..., Vn selected in this way with the detection output, that is, the holding voltage VH, and outputs an output indicating the magnitude relationship. can get. This output is analog / digital conversion data.

As means for storing the successively converted data, a successive conversion register 120 is provided. The successive conversion register 120 is means for temporarily storing digital data obtained by successive conversion. An A / D result register 122 is provided as means for storing digital data from the successive conversion register 120. The A / D result register 122 stores digital data from the successive conversion register 120, and always stores new data.

The comparison register 124 stores A / D
The data in the result register 122 has been transferred, and the contents thereof are stored as the data before the data in the A / D result register 122. The data processing here is A /
The new data in the D result register 122 is compared with the current data in the comparison register 124. If the difference between the two is within the resolution range, that is, the error range, the comparison register 1
The current data stored in 24 is determined as true data. A determination register 126 is provided as a means for storing the determined data, and digital data of the detection output is stored in the determined register 126. These data processes are executed by the CPU 62, and 128 is its internal bus.

The operation will be described based on the above configuration.

FIG. 4 is a flowchart showing the general operation. Initial setting is performed by turning on the power,
After this initial setting, it is determined in step S1 whether or not a hot water supply operation is to be performed. In the case of the hot water supply operation, the process proceeds to step S2 to execute the hot water supply operation, and it is determined in step S3 whether or not the water level in the bathtub 12 is a predetermined water level. As shown in FIG. 2, the predetermined water level is set for the remote controller 92, and it is determined whether or not the water level is the set water level. In the hot water supply operation, when the water level in the bathtub 12 reaches a predetermined water level, the hot water supply operation is stopped.

If it is determined in step S1 that the operation is not the hot water supply operation, the process proceeds to step S4 (FIG. 6) to perform the warming operation. This warming operation is an operation for keeping the temperature of the hot water in the bathtub 12 at the set temperature, and is an operation for always maintaining the optimum hot water temperature.

FIG. 5 shows the hot water supply operation in step S2, and shows the hot water supply circuit 4 being opened.
The clean water W is heated by the hot water supply heat exchanger 16 and then supplied to the bathtub 12 from the bathtub going pipe 8 through the opening / closing solenoid valve 22, the pressure feed hopper 24, and the switching valve 26. In this case, as shown by the broken line, the bathtub return pipe 10 is also filled with the hot water HW in the bathtub 12. As a result, the temperature of the hot water HW by the temperature sensor 32 and the water level in the bathtub 12 by the water level sensor 34 are detected. Is done. In this hot water supply operation, normally, in order to reduce the temperature due to heat dissipation and shorten the additional heating time at the time of hot water supply, the hot water supply is performed at a hot water temperature higher by 0.5 ° C. depending on the set temperature, and the water is shifted to a predetermined water level. At this time, after the temperature is detected at the time of completion of hot water supply, the operation automatically shifts to the reheating operation in the same manner as the heat retention operation, and the hot water in the bathtub 12 is controlled to the set temperature.

Next, FIG. 6 shows the warming operation in step S4 of FIG. This warming operation is an operation of maintaining the set temperature by heating hot water or hot water HW in the supplied bathtub 12 to the set temperature.
The warming operation indicates a reheating operation after the previous hot water supply operation and the reheating operation.

In step S11, it is determined whether or not a predetermined time, that is, a standby time (Tb in FIG. 10) has elapsed after the completion of the additional heating. This standby time is a temperature set after the temperature reaches the set temperature, taking into account the heat retention of the hot water. After the elapse of the standby time, the process proceeds to step S12, and the reheating operation is performed. Then, in step S13, the warming time is monitored, and the process returns to step S11 before the warming time has elapsed, and the warming operation is stopped after the warming time has elapsed. The warming operation is based on the assumption that there are a plurality of bathers, and since the time during which a plurality of people take a bath can be managed to some extent, the warming time is set in advance. That is,
Before the heat retention time has elapsed, reheating is repeatedly performed. After the heat retention time has elapsed, the heat retention operation is stopped.

FIG. 7 shows the reheating operation in the heat retention operation, and shows the open state of the reheating circuit 6. The reheating operation is a process for reheating the hot water in the bathtub 12, and the circulation pump 2 is connected to the reheating heat exchanger 18.
In step 8, the hot water HW in the bathtub 12 is circulated and heated. That is, the hot and cold water HW in the bathtub 12 is drawn by the circulation pump 28 through the bathtub return pipe 10, is pressure-fed to the heat exchanger 18 for additional heating, and is heated. 8 returns to the bathtub 12. By repeating such pressure feeding circulation, the hot water HW in the bathtub 12 is heated to the set temperature.

Next, FIG. 8 shows a reheating operation. In step S21, the circulation pump 28 is operated to circulate the hot water HW in the bathtub 12 to the additional heating circuit 6. This circulation of hot and cold water is detected by the flowing water switch 38.
Therefore, in step S22, it is determined whether or not flowing water has been detected, and if not detected, the flow proceeds to step S23. If running water cannot be detected even though the circulation pump 28 is driven, it is determined that an abnormality has occurred, and step S23 is performed.
Then, the abnormality is displayed or notified by sound using the display unit 100 or the sound output unit 98.

If the detection of flowing water is detected, the flow shifts to step S24 to determine whether the detected temperature is lower than the set temperature. If the detected temperature exceeds the set temperature, the process proceeds to step S25, in which it is determined whether a predetermined time has elapsed.
Judgment is maintained. If the detected temperature exceeds the set temperature even after the lapse of the predetermined time, the flow goes to step S32 to stop the circulation.

If the detected temperature is lower than the set temperature, the flow shifts to step S26 to start additional combustion.
That is, after starting the ignition operation, the gas on-off valve 52 is opened to ignite the reburning burner 50. As a result of this additional combustion, the process proceeds to step S27, where it is determined whether the detected temperature is equal to or higher than the set temperature. When the detected temperature is detected to be equal to or higher than the set temperature, the process proceeds to step S28 and the time Perform measurement. This time measurement is performed by the CPU 62, for example, by measuring a clock pulse. The purpose of this time measurement is to confirm that the detected temperature fluctuates, and that the temperature rise has continued for a predetermined time.

In step S30, it is determined whether a predetermined time has elapsed. Until the predetermined time has elapsed, the process returns to step S27 to compare the detected temperature with the set temperature. If the detected temperature has become equal to or lower than the set temperature within the predetermined time in step S27, the process proceeds to step S29, in which the time measurement is stopped, and the measured time is reset. That is, the measurement of the clock pulse is returned to zero, and the operation is continued.

If the detected temperature has reached or exceeded the set temperature in step S30, and if the detected temperature has continued for a predetermined time, the process proceeds to step S31 to stop the additional combustion. That is, hot water H in the bathtub 12
When the temperature of W reaches the set temperature, the reheating operation is stopped. After the stop of the reburning combustion, step S3
The operation proceeds to 2, and the operation of the circulation pump 28 is stopped with a delay of a fixed time from the stop of the reheating combustion, and the reheating operation is stopped.

FIG. 9 shows a temperature detecting operation. In this temperature detection operation, the bathtub 12 during hot water supply and warming is maintained.
The temperature of the hot and cold water HW is detected. In step S41, the detected temperature is taken in. In step S42, the detected temperature is stored in the RAM 66. In this embodiment, for example, fetching and storing are performed about 10 times.

Then, in step S43, the average value is calculated. Assuming that the number of detected temperatures taken is m times and the taken-in detected temperatures are H1, H2,..., Hm, addition is performed except for the detected values of the maximum value and the minimum value in the m times, and the added value is obtained. If ΣH, the sum is (m−
Dividing by 2) gives the average value {= {H / (m-2)}. Then, in step S44, this average value is stored in the RAM.
66 and the temperature detection is completed.

Next, FIG. 10 shows the operation timing when shifting from the additional heating operation at the time of hot water supply to the warming operation.

The time Ta represents the reheating operation time,
During this time, as shown in FIG. 10A, the gas on-off valve 52 is opened, and gas combustion for reheating is performed. When the hot water HW in the bathtub 12 reaches the set temperature, the gas on-off valve 52 is closed and the combustion operation is stopped.

Then, as shown in FIG. 10B, after a time Td from the stop of the circulation pump 28, the circulation pump 28
Stops. The reason why the operation of the circulation pump 28 is stopped is delayed by the time Td from the closing of the gas on-off valve 52 in order to avoid the post-boiling boiling due to the heat of the reheating heat exchanger 18, This is because the temperature inside the heat exchanger 18 is reduced.

After the circulation pump 28 is stopped, FIG.
(C), the detection of the flowing water by the flowing water switch 38 is stopped.

Then, a standby time Tb of a predetermined time is started from the stop of the gas on-off valve 52. This waiting time Tb is
For example, it is set to about 30 minutes. When the standby time Tb elapses, the circulation pump 28 is operated to circulate the hot water HW in the bathtub 12 to the additional heating circuit 6. The time Te is a stop time of the circulation pump 28, and the stop time Te is shorter than the standby time Tb.

When the circulation of the pump is started, as shown in FIG. 10C, the detection of the flowing water of the flowing water switch 38 is performed simultaneously with the start of the operation of the circulating pump 28. Assuming that a point in time when the detection of flowing water is performed is to, a comparison between the set temperature and the detected temperature is performed at this point in time to. The detected temperature used for this comparison is stored in the RAM 66 immediately before the time point to.
, That is, the detected temperature updated as a result of the calculation immediately before performing the pump circulation.

Incidentally, the temperature detection is always performed.
The detection is performed, for example, every 0.5 seconds, and assuming that the average value is calculated in units of, for example, 10 temperature acquisitions, the detected temperature to be compared is about 5 seconds before the time point to from the time point to. This is the average temperature obtained by taking the temperature up to immediately before.

As a result of the comparison between the detected temperature and the set temperature, if the detected temperature is lower than the set temperature, the time t
The operation shifts to the ignition operation during a time Tf after o, and the gas on-off valve 52 is opened as shown in FIG. As a result, the reheating operation, that is, the heat retaining operation is started, and the time T
c is the heat retention operation time. This warming operation continues until the detected temperature reaches the set temperature.

Next, FIG. 11 shows a comparison operation between the set temperature and the detected temperature. In FIG. 11, a straight line L indicates a transition of the detected temperature, which fluctuates greatly in practice, but is indicated by a straight line for ease of explanation, an arrow UP indicates an ascending direction, and an arrow DN indicates a descending direction. It is. Also,
As for the temperature, 39 ° C. to 43 ° C. are shown as typical values for easy explanation.

The set temperature is arbitrarily set in units of 1 ° C., and the value is displayed on the display unit 100 together with the unit. The set temperature has, for example, a temperature range T1 of 0.5 ° C., and a temperature range T2 = 0.5 ° C. is set as a non-set temperature between the set temperatures. In this case, set temperature = 38.75 to 39.25 ° C., non-set temperature = 39.25
° C to 39.75 ° C, set temperature = 39.75 to 40.25
° C, non-setting temperature = 40.25 ° C-40.75 ° C ...
Is set. That is, the set temperature is 39 ° C., 40
.., 41 ° C., 42 ° C., etc., the set temperature itself has a range of 0.5 ° C., and is not a temperature value as an absolute value.

On the other hand, the hot and cold water temperature is an analog value that is continuously converted, and the detected temperature is also continuous. However, due to the analog-to-digital conversion, the acquisition of the detected temperature takes place at regular time intervals, e.g.
This is performed every ms, and is taken in as a continuous value. Then, the temperature is acquired by converting a change in the resistance value of the thermistor 102 into a voltage value, and is acquired at intervals of 0.5 ° C. in units of about 20 mV. As a result, the detected temperature AD
The converted values are taken in at 20 mV intervals corresponding to 0.5 ° C. intervals and converted into digital data. In FIG. 11, d38.5 to d43 indicate detection data representing the detected temperature. Theoretically, the voltage value representing the detected temperature is shown in FIG.
There is a case where it matches the horizontal line in 1, but this is taken in as higher-order data as an error in data processing. For example, the data on the line representing 40.25 ° C. is d40.5.

The A / D conversion value indicating the detected temperature and the A / D conversion value at the set temperature are compared.
In the example of FIG. 11, the set temperature is 41 ° C.
Assuming that the conversion value is D41, the AD conversion value d3 of the detected temperature
8.5 to d43. As a result of the heat retaining operation, when the detected temperature of the hot or cold water reaches d41, the detected temperature matches the AD conversion value D41 representing the set temperature, and after the coincidence has elapsed for a predetermined time,
It stops the warming operation.

When the temperature of the hot and cold water in the bathtub 12 decreases during the standby time and the detected temperature decreases to, for example, d40,
The operation shifts to the heat keeping operation, and the additional heating operation is performed until the detected temperature reaches the set temperature D41.

As described above, the set temperature has a constant temperature range T1.
(= 0.5 ° C.), and a constant temperature width T2 (= 0.5 ° C.) is set between the set temperatures. Moreover, the temperature widths T1 and T2 are T1 = T2, and the resolution (for example, 20 m
V). In addition, since a certain temperature range is set between the set temperatures, the operation at the time of analog-digital conversion is stabilized, and after a certain period of time, the reheating operation or the stop thereof is performed. The safety of operation can be improved without repeating the 50 point fire extinguishing.

In the embodiment, the interval between the set temperatures is made to coincide with the resolution of the analog / digital conversion means, but a temperature width exceeding the resolution may be set.

[0067]

As described above, according to the present invention,
The following effects can be obtained. a. Since the transition to the heat retention operation is determined based on whether the detected temperature has dropped below the set temperature, the heat retention control can be performed as quickly as possible, and in the heat retention operation, normal reheating control is used. In addition, the temperature of the hot and cold water in the bathtub can be easily controlled to the set temperature. Moreover, the set temperature is not the absolute value of the set temperature plus the permissible temperature, but has a fixed temperature range itself, and shifts to the warming operation when the detected temperature matches or does not match the set temperature. Control
And the time when the detected temperature continuously exceeds the set temperature
Measure and keep warm until the measurement time elapses
Keep the temperature of the hot water in the bathtub at the set
Can be maintained. b. The heat retention operation can be performed quickly by digital processing, and the set temperature is set to a temperature width equivalent to the resolution of the analog-to-digital converter that converts the detected temperature to digital. The comparison process is facilitated, the accuracy is increased, highly reliable temperature control can be realized, and the safety of the heat retaining operation can be further improved. c. The detected temperature is analog-to-digital converted and compared with the set temperature that is set stepwise, and it is possible to easily and accurately judge whether the two coincide or not with each other. There is no need to set an allowable temperature with respect to the set temperature, and it is possible to realize temperature control suitable for human temperature sensation.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a temperature control device for hot and cold water in a bathtub according to the present invention.

FIG. 2 is a block diagram showing a control circuit of the temperature control device for hot and cold water in a bathtub according to the present invention.

FIG. 3 is a block diagram illustrating a configuration of an analog-to-digital converter.

FIG. 4 is a flowchart showing an initial operation.

FIG. 5 is a system diagram showing an operation of the hot water supply circuit.

FIG. 6 is a flowchart showing a warm-up operation.

FIG. 7 is a system diagram showing an operation of the additional heating circuit.

FIG. 8 is a flowchart showing a reheating operation.

FIG. 9 is a flowchart showing temperature detection.

FIG. 10 is a timing chart showing a warming operation.

FIG. 11 is a diagram showing a comparison operation between a set temperature and a detected temperature.

[Explanation of symbols]

 Reference Signs List 8 bathtub outgoing pipe (circulation path) 10 bathtub return pipe (circulation path) 12 bathtub 18 heat exchanger for additional heating 28 circulation pump 32 temperature sensor 50 burner for additional heating 52 gas open / close valve (control valve) 60 control unit (control means) ) 72 Analog / Digital Converter

Continuation of front page (56) References JP-A-5-10584 (JP, A) JP-A-4-32653 (JP, A) JP-A-4-353342 (JP, A) JP-A-2-9333 (JP) , Y2) (58) Field surveyed (Int. Cl. ⁶ , DB name) F24H 1/00 302

Claims (5)

(57) [Claims] 1. A bath tub and a heat exchanger are connected by a circulation path, and hot water in the bath tub is circulated to the heat exchanger by a circulation pump provided in the circulation path and heated to control the set temperature. A temperature control device for hot and cold water in a bath tub, wherein the burner heats the heat exchanger by burning supplied fuel gas, a control valve for switching the supply of the combustion gas to the burner, and a control valve provided in the circulation path. A temperature sensor for detecting the temperature of the hot and cold water, and after the hot water in the bath tub reaches a set temperature and a certain period of time has elapsed from the stoppage of combustion of the burner, the circulating pump is operated to operate the circulating passage. staying in the circulation path in the both the start circulating the circulating hot water in the bathtub
The temperature is detected by the temperature sensor and the set temperature
If the detected temperature is lower than the set temperature,
Opens the control valve to cause the burner to perform a combustion operation,
If the detected temperature is equal to or higher than the set temperature, the hot water
After continuing the water circulation for a predetermined time, the temperature of the hot water in the bathtub
When it is detected that the temperature is lower than the set temperature,
The combustion circuit, and circulates through the circulation path during the combustion operation.
The temperature rise of the hot and cold water is detected by the temperature sensor,
A control unit that measures a time when the detected temperature is continuously equal to or higher than the set temperature, and performs a heat retention control that closes the control valve and stops the combustion operation of the burner when the measured time exceeds a predetermined time, A temperature control device for hot and cold water in a bathtub, comprising: 2. The control means starts time measurement from the time when the temperature detected by the temperature sensor becomes equal to or higher than the set temperature during the combustion operation of the burner. The temperature control of the hot and cold water in the bathtub according to claim 1, wherein the measurement time is reset when the temperature becomes lower than the temperature, so that the time when the detected temperature continuously exceeds the set temperature is measured. apparatus. 3. The temperature control device according to claim 1, wherein the processing by the control means is performed by converting the set temperature and the detected temperature into digital data and performing digital processing. 4. The hot and cold water in a bath tub according to claim 3, wherein the set temperature has a unit of resolution of an analog-to-digital converter for converting the detected temperature into a digital value and has a temperature width equivalent to the resolution. Temperature control device. 5. A temperature range equal to or exceeding the resolution of the analog-to-digital converter is set in an interval between the set temperatures set in a stepwise manner. A temperature control device for hot and cold water in a bathtub as described in the above.