JP3087205B2 - Circulating bath kettle controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced circulation bath for heating the circulated water by forcibly circulating water in a bathtub, and more particularly to controlling the circulation bath. The present invention relates to a control device.

[0002]

2. Description of the Related Art Conventionally, water in a bathtub is forcibly circulated by a pump and a heat exchanger provided in a circulation line is heated by combustion to raise the water in the bathtub to a predetermined temperature. A forced circulation bath is used. FIG. 3 shows an example of a heat exchanger for heating water in a pipeline by gas combustion.
FIG. The water F circulated by the pump is sent to a heat exchanger 50 provided at an upper part of the gas combustion chamber 31,
There it is heated and returned to the bathtub. That is, water F is
It enters the lower pipe 41a from the right end of the heat exchanger 50, goes to the left end of the heat exchanger 50, and returns to the right end by the lower pipe 41b. Then, it goes to the left end by the lower pipe 41c and returns to the right end by the middle pipe 42a. The water F is repeatedly returned to the outside through the upper pipe 43c and returned to the bathtub.

[0003] In a normal forced-circulation bath kettle, the circulating flow rate of water F is 5 to 8 liter / min, and the amount of water in the bathtub is 18
0-200 liters, gas burning amount about 12000kc
al / hour, the circulation flow rate of water is 5 liters /
In the case of min, the water temperature rises by about 30 degrees Celsius between entering and exiting the heat exchanger 50 (hereinafter, Celsius is omitted). Thus, the bathtub water temperature gradually rises by the forced circulation heating. The water temperature in the bathtub is detected by a thermistor provided on the inlet side of the heat exchanger 50. Then, when the thermistor detects a predetermined temperature, the forced circulation and the gas combustion are automatically stopped.

[0004]

However, the conventional circulating bath kettle and its control device have the following problems. That is, there was a case where partial boiling of water F occurred in the pipe in the heat exchanger. For example, consider a case in which a circulation bath is started when the temperature of water F in a bathtub is about 10 degrees. The water temperature of the water F flowing into the heat exchanger is about 10 degrees, but when the amount of circulating water is 5 liters / min, the water temperature of the water F flowing out of the heat exchanger increases by about 30 degrees to about 40 degrees. . When the temperature of the water F in the bathtub rises to about 40 degrees, the temperature of the water F flowing into the heat exchanger becomes about 40 degrees, and the temperature of the water F flowing out of the heat exchanger is about 70 degrees, which is a very high temperature. become.

However, at this time, the water temperature of the water F in the copper pipe of the heat exchanger is not uniform. This is because the water F circulated by the pump is heated from the outer peripheral side in contact with the inner wall of the copper pipe in the pipeline. For this reason, the water temperature of the water F in the copper pipe has considerable unevenness, and the above-mentioned outflow water temperature is a kind of average water temperature. When the average water temperature is close to 70 degrees, the water temperature near the pipe inner wall near the heat exchanger outlet of the copper pipe may reach 100 degrees. At this time, partial boiling occurs. When partial boiling occurs, the pressure in the copper pipe of the heat exchanger rises, and there is a problem that the durability of the copper pipe is reduced. In addition, an unpleasant noise (so-called "biting noise") is generated from the heat exchanger, and this noise can be heard from the bathroom. Absent. In addition, high-temperature hot water may flow into the bathtub without eliminating such nonuniform water temperature, which is not preferable because people enter the bathtub.

According to the present invention, partial boiling does not occur in the heat exchanger even when the temperature of the water in the bathtub rises, and the circulation of the heat exchanger prevents deterioration of durability, generation of abnormal noise, or inflow of high-temperature hot water into the bathtub. It is an object of the present invention to provide a bathtub controller.

[0007]

SUMMARY OF THE INVENTION To achieve this object, a circulation bath controller of the present invention is provided with a forced circulation device for forcibly circulating water in a bathtub, and a forced circulation device provided in the pipeline of the forced circulation device. A heat exchanger, and a circulation bath controller that controls a circulation bath having a gas combustor that heats the heat exchanger, and an outlet water temperature detector that measures the temperature of water that is heated and returned to the bathtub. A flow rate varying means for varying an amount of water circulated by the forced circulation device, and a portion for determining whether or not the water temperature measured by the outlet water temperature detector is a temperature at which partial boiling of water can occur in the pipeline. Boiling determination means, by increasing the flow rate of water through the flow rate variable means when the measured water temperature of the outlet water temperature detector is determined by the partial boiling determination means to be a temperature at which partial boiling can occur. Outlet water temperature And it has a flow control means for maintaining below.

[0008]

The forced circulation device of the circulation bath controller of the present invention having the above-described structure circulates and heats the water in the bathtub through the heat exchanger. The outlet water temperature detector measures the temperature of the water that is heated and returns to the bathtub. The flow rate varying means varies the amount of water circulated by the forced circulation device.

Here, the partial boiling judging means judges whether or not the water temperature measured by the outlet water temperature detector is a temperature at which partial boiling of water can occur. If it is determined that the temperature is such that partial boiling can occur, the flow control means increases the flow rate circulated by the forced circulation device via the flow rate control means. In this way, the rise of the water temperature in the heat exchanger is reduced, and the unevenness of the water temperature in the pipeline is reduced. As a result, even when the temperature of the bathtub is rising, the outlet water temperature can be prevented from excessively rising and can be maintained at a predetermined temperature or less, so that there is no occurrence of partial boiling in the copper pipe and the durability is reduced. No hot water or hot water flows into the bathtub.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a circulating bath controller according to an embodiment of the present invention; FIG. 1 shows the overall configuration of the circulation bath kettle. The bathtub 24 stores a certain amount of water F. A bus adapter 45 is formed below the inner wall of the bathtub 24 to allow the water F to flow in and out. The return pipe 27 is connected to the center of the bus adapter 45. The return pipe 27 is connected to a pump 15 for circulating water. The pump 15 is connected to a pump drive circuit 32 for controlling the amount of circulating water.
A bath tub temperature thermistor 26 for detecting the water temperature in the bath tub is provided at a position upstream of the pump of the return pipe 27.

The return pipe 27 is introduced into a heat exchanger 50 provided above the gas combustion chamber 31. Heat exchanger 50
As shown in FIG. 3, the copper pipe 28 provided in the combustion chamber is connected to the end of the heat exchanger 50 from end to end, as shown in FIG.
It is configured to reciprocate twice. That is, the copper pipe 28
Are the lower pipes 41a, 41b, 41c, the middle pipe 4
2a, 42b and the upper pipes 43a, 43b, 43c make four round trips in the heat exchanger 50. Copper fins 21 for heat collection are formed on the outer wall of the copper pipe 28.

In the circulating bath kettle of this embodiment, the standard flow rate of water F is 5 liter / min, and the amount of water in the bathtub is 18
0-200 liters, gas burning amount about 12000kc
al / hour. At this time, the water temperature rises by about 30 degrees when entering and exiting the heat exchanger 50. Heat exchanger 50
Is connected to an outgoing pipe 25 for returning circulating water to the bathtub. A tap water temperature thermistor 1 for measuring the temperature of the water that has risen in temperature in the heat exchanger 50 near the exit of the gas combustion chamber 31 of the going pipe 25.
4 is attached. The going pipe 25 is connected to the outer peripheral portion of the return pipe 27 of the bus adapter 45.

Next, the flow path of propane gas G as a combustion gas will be described. The gas pipe 29 is connected to a propane gas tank (not shown). The gas pipe 29 is connected to the main solenoid valve 13 which is a main plug of gas. Gas pipe 29
Is introduced into the gas combustion chamber 31. Gas combustion chamber 3
A nozzle 18 for ejecting the gas G is formed at the lower end of the gas pipe 29 at the lower end of the gas pipe 29. Nozzle 1
A burner 17 is fixedly provided in the ejection direction of the nozzle 8. An electrode 16 for generating a spark that ignites the gas G is provided near the upper portion of the burner 17. Gas combustion chamber 31
An air duct 30 is attached to the lower right side of the air conditioner. The blower duct 30 is provided with a fan 12 for supplying combustion air. The fan 12 is connected to a fan motor drive circuit 11. An exhaust top 23 for discharging combustion exhaust gas is formed on the upper right side of the gas combustion chamber 31.

Next, FIG. 2 is a block diagram showing the configuration of the circulating bath kettle control device of this embodiment. A controller 35, which is a main part of the control device, includes a CPU 36 for performing arithmetic processing,
It comprises a ROM 37 for storing a control program and a RAM 38 for temporarily storing data and the like. ROM3
7, a water amount variable program 48 for controlling the flow rate of the water F is stored. The controller 35 receives as input the tap water temperature thermistor 14 and the bathtub water temperature thermistor 2
6 are connected. Also, as outputs, a pump drive circuit 32 for controlling the pump 15, a fan motor drive circuit 11 for controlling the fan 12, and the original solenoid valve 13
Is connected.

Next, the operation of the circulating bath kettle control device having the above configuration will be described. Fill the bath with water F to an appropriate depth. Next, switch on the controller 35 is turned on,
Start gas combustion. That is, the controller 35 opens the original solenoid valve 13 and jets a certain amount of propane gas G from the nozzle 18 to the burner 17. At the same time, a voltage is applied to the electrode 16 and a spark is generated, so that the propane gas G
Is ignited. Further, the fan motor drive circuit 11 drives the fan 12 to blow combustion air to the gas combustion chamber. The pump drive circuit 3 receives a command from the controller 35.
2 drives the pump 15 at a constant rotational speed m and circulates a constant flow of water F through the copper pipe 28 in the heat exchanger 50. The temperature of the flue gas immediately after the combustion of the propane gas G is about 1300 degrees, which corresponds to the temperature of the copper pipe 2 in the heat exchanger 50.
8 contacts the outer wall. As a result, the water F
Heat is exchanged through the copper pipe 28.

The temperature rise of the water F at this time (hereinafter referred to as the "inflow / outflow temperature difference") differs depending on the flow rate of the drive of the pump 15. The flow rate is large when the flow rate is high, and small when the flow rate is small. Is big. The inflow / outflow temperature difference at the standard flow rate N is about 30 degrees. In the early stage of the combustion, the temperature of the water F stored in the bathtub 24 is about 10 degrees, and the temperature of the water F initially flowing through the return pipe 27 is the same. Therefore, at this time, the temperature of the water F flowing into the lower pipe 41a of the copper pipe 28 (hereinafter, referred to as “entrance temperature Ti”) is 10
Degrees. Thus, the temperature of the water F flowing into the going pipe 25 (hereinafter, referred to as “outlet temperature To”) is from 10 degrees to about 30 degrees.
It rises to about 40 degrees.

A controller 35 which is a main part of the present invention
Controls the flow rate of the water F based on the feedback value of the tapping temperature thermistor so that the outlet temperature To does not exceed 65 degrees. If the temperature exceeds 65 degrees, the water temperature reaches 100 degrees in a part of the copper pipe 28, and partial boiling occurs. The control method will be described with reference to the flowchart shown in FIG. The outlet temperature of the water F discharged from the gas combustion chamber is set in the RAM 38 of the controller 35 (S1). This outlet temperature set value Tc
Is determined so that the maximum water temperature in the copper pipe 28 does not exceed 100 degrees. In the circulating bath kettle of this embodiment, by setting the outlet temperature set value Tc to 65 degrees, the maximum water temperature in the copper pipe 28 can be maintained so as not to reach 100 degrees, and the occurrence of partial boiling can be suppressed. Has been confirmed by experiments. The outlet set temperature Tc = 65 degrees is stored in the ROM 37.

When the circulating bath kettle is started, the controller 35 detects the outlet temperature To by the hot water temperature thermistor 14 (S2). Here, as an example, consider a case where a bath is heated by a circulating bath kettle from a state where the water temperature is 10 degrees.
Since the flow rate of the pump 15 at the beginning is the standard flow rate N, the outlet temperature To rises by 30 degrees from the inlet temperature Ti to 40 degrees. Here, the outlet temperature To = 40 degrees and the set temperature T
Since c is lower than 65 degrees (S3, No), the controller 35 reduces the rotation speed of the pump 15 via the pump drive circuit 32 to reduce the flow rate of the water F by the water amount variable program 48 (S5). When the rotation speed of the pump 15 is reduced,
As the amount of circulating water is reduced, the temperature difference between inlet and outlet increases,
The outlet temperature To rises. Then, since the inlet temperature Ti further increases due to the increase in the water temperature in the bathtub 24 due to the circulation heating, this also increases the outlet temperature To.

When the outlet temperature To approaches the set temperature Tc (65 degrees), the rotation speed of the pump 15 is not further reduced. When the outlet temperature To becomes equal to or higher than the set temperature Tc (S3, Yes), the rotation speed of the pump 15 is increased (S3).
4). As a result, the flow rate increases, the difference between the inlet and outlet temperatures decreases, and the outlet temperature To decreases. Thus, the outlet temperature To is prevented from exceeding the set temperature Tc (65 degrees). Thereby, even if the water temperature in the bathtub 24 rises, the outlet temperature To
Is prevented from exceeding 65 ° C., and the maximum water temperature in the copper pipe 28 of the gas combustion chamber 31 is maintained so as not to reach 100 ° C. due to the effect of turbulence due to the increase in flow rate, thereby preventing the occurrence of partial boiling. Can be. Thus, generation of abnormal noise from the heat exchanger 50 and inflow of high-temperature hot water into the bathtub 24 can be prevented.

In this embodiment, the flow rate is controlled so that the outlet temperature To is maintained at the set temperature Tc. However, the processing in step 5 is omitted and the outlet temperature To is controlled so as to be lower than the set temperature Tc. May be. Also, the upper and lower limit values may be set so that the outlet temperature To falls within a predetermined range (for example, 40 degrees or more and 65 degrees or less). In this case, it is natural that the maximum temperature is set so that the maximum water temperature in the copper pipe 28 does not reach 100 degrees. When the minimum temperature is determined, it is preferable to set the outer wall temperature of the copper pipe 28 so as not to be lower than the dew point temperature in the heat exchanger 50. Providing the lower limit for the set temperature has the advantage that corrosion of the copper pipe 28 due to condensation in the heat exchanger 50 can be prevented.

Next, a description will be given of a circulating bath kettle control device according to a second embodiment. The basic configuration and operation are the same as those of the circulating bath kettle control device of the first embodiment, and therefore only different points will be described, and description of the same portions will be omitted. As a feature of the second embodiment, as shown in FIG. 6, as a method of increasing or decreasing the flow rate of the water F flowing in the copper pipe 28, a flow control for adjusting the flow rate between the pump 15 and the heat exchanger 50 is performed. The point is that a water control valve 46 as a valve is provided. The water control valve 46 is a flow control valve that allows the water F of an arbitrary flow rate to flow by changing the gap between the valve seat and the valve body by moving the valve body by a motor, for example. In this case, the output of the pump 15 is fixed, and the flow rate of the water F flowing through the copper pipe 28 is controlled by the controller 35 through the flow rate control circuit 47 by the flow rate control program.

That is, as shown in the flowchart of FIG. 5, when the circulating bath kettle is started, the controller 35
After the outlet temperature set value Tc is determined (S11), the outlet temperature To is detected by the tapping water temperature thermistor 14 (S1).
2). Here, as an example, consider a case where a bath is heated by a circulating bath kettle from a state where the water temperature is 10 degrees. Since the opening degree of the water control valve 46 is the standard flow rate N, the outlet temperature To rises by 30 degrees from the inlet temperature Ti (10 degrees) to 40 degrees. Here, the outlet temperature To = 40 degrees and the set temperature T
Since c is not higher than 65 degrees (S13, No), the controller 35 reduces the flow rate of the water F by reducing the opening of the water control valve 46 via the flow rate control circuit 47 by the water flow rate variable program 48 (S15). As the circulating water volume is reduced, the difference between the inlet and outlet temperatures increases, and the outlet temperature To rises.

Next, when the outlet temperature To becomes higher than the set temperature Tc by continuing the circulating heating (S13, Y
es), the opening of the water control valve 46 is opened (S14). Thereby, even if the water temperature in the bathtub 24 rises, the outlet temperature To
Is prevented from exceeding 65 degrees, and turbulence is generated in the copper pipe 28 due to an increase in the flow rate.
Of the water F in the copper pipe 28 can be prevented from being partially boiled. Thus, generation of abnormal noise from the heat exchanger 50 and inflow of high-temperature hot water into the bathtub 24 can be prevented.

In this embodiment, as in the first embodiment, the process at step 15 is omitted and the outlet temperature To is reduced to the set temperature Tc.
Control may be performed as follows. Also, the outlet temperature To
May be set to a predetermined range (for example, 40 degrees or more and 65 degrees or less). According to the present embodiment, the pump can be operated at a constant level as compared with the first embodiment.
There is an advantage that control becomes easy. As described above, the present invention has been described with respect to some embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be easily made without departing from the spirit of the present invention. It can be inferred. For example, in the present embodiment, the method of changing the rotation speed of the pump and the method of controlling by the motor flow rate control valve have been described as the flow rate control method, but the gap between the valve body and the valve seat is changed by changing the voltage applied to the coil. A method using a voltage proportional valve for changing the voltage may be used.

[0025]

As is apparent from the above description, the circulation type bath kettle control device of the present invention has a flow rate varying means for varying the amount of water circulated by the forced circulation device, and an outlet water temperature in the pipeline. Partial boiling determination means for determining whether or not the temperature is such that partial boiling can occur; and through the variable flow rate means when the outlet water temperature is determined by the partial boiling determination means to be a temperature at which partial boiling can occur. Flow rate control means for maintaining the outlet water temperature at or below a predetermined temperature by increasing the flow rate of water, so that the outlet temperature is maintained at or below the predetermined temperature even when the water temperature of the bathtub rises, and Increasing the flow rate in the road to reduce water temperature non-uniformity does not cause partial boiling in the heat exchanger and prevents durability deterioration, generation of abnormal noise, or inflow of hot water into the bathtub be able to.

[Brief description of the drawings]

FIG. 1 is a drawing showing a configuration of a circulation type bath kettle control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a circulation type bath kettle control device.

FIG. 3 is a sectional view showing a configuration of a combustor.

FIG. 4 is a flowchart showing the operation of the circulation type bath kettle control device of the first embodiment.

FIG. 5 is a flowchart showing the operation of the circulation type bath kettle control device of the second embodiment.

FIG. 6 is a drawing showing a configuration of a circulation type bath kettle control device according to a second embodiment.

[Explanation of symbols]

 14 Hot water temperature thermistor 15 Pump 24 Bathtub 26 Bath water temperature thermistor 28 Copper pipe 31 Gas combustion chamber 32 Pump drive circuit 35 Controller 46 Water control valve 47 Flow rate control circuit 48 Water volume variable program 50 Heat exchanger

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-204062 (JP, A) JP-A-54-22272 (JP, A) JP-A-6-147633 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) F24H 1/00 602

Claims (1)

(57) [Claims] 1. A circulating bath having a forced circulation device for forcibly circulating water in a bathtub, a heat exchanger provided in a pipeline of the forced circulation device, and a gas combustor for heating the heat exchanger. An outlet water temperature detector for measuring a temperature of water heated and returned to the bathtub; a flow rate variable means for varying an amount of water circulated by the forced circulation device; and the outlet water temperature detector. Means for determining whether or not the water temperature measured is a temperature at which partial boiling of water can occur in the pipeline, and the measured water temperature of the outlet water temperature detector is determined by the partial boiling determining means. Flow rate control means for maintaining the outlet water temperature at or below a predetermined temperature by increasing the flow rate of water through the flow rate variable means when it is determined that the temperature can be generated. Bath kettle Control device.