JP3087206B2 - 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 bathtub for forcibly circulating water in a bathtub and heating the circulated water, and more particularly, to heating the circulation bathtub water. The present invention relates to a control device for controlling.

[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.

In a normal forced circulation bath, for example, the circulating flow rate of water F is 5 to 8 liters / min, the amount of water in a bathtub is 180 to 200 liters, and the amount of gas combustion is about 1200.
At 0 kcal / hour, when the circulation flow rate of water is 8 liters / min, the water temperature rises by about 19 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 measured by a thermistor provided between the inlet of the circulation pipe and the gas combustion chamber 31. Then, when the thermistor measures a predetermined temperature, the forced circulation and the gas combustion are automatically stopped.

[0004]

However, the conventional circulation type bath kettle and its control device are corroded by water droplets (condensation) generated around heat exchange copper pipes and fins. Problem. For example, consider a case where the circulation bath is started to be fired when the temperature of the water F in the bathtub is about 10 degrees in winter or the like. When the circulation flow rate is 8 liters / min, the water temperature in the lower pipe is 10 degrees, but the temperature of the combustion exhaust gas is as high as about 1300 degrees immediately after combustion, so that the surface of the heat exchange fins is 150 to 18 degrees.
It becomes 0 degree, and does not become lower than the dew point temperature (for example, 55 degrees) of the combustion exhaust gas. However, the temperature of the combustion exhaust gas is gradually reduced by performing the heat exchange. As a result, the temperature of the flue gas drops below the dew point temperature due to surface contact with the fins while passing through the upper part of the heat exchanger, and water droplets adhere to the outer walls of the copper pipe and the fins. Therefore, there has been a problem that nitrogen oxides and sulfur oxides, which are easily contained in the combustion exhaust gas, dissolve in the water droplets and corrode copper pipes and fins.

According to the present invention, even when the water temperature is low in winter, the temperature of the circulating water is maintained at a predetermined temperature or more quickly from the start of the circulation type bathtub, and the temperature of the outer wall of the copper pipe or the copper fin is reduced. An object of the present invention is to provide a circulating bath kettle control device in which a copper pipe or a copper fin is not corroded when the temperature is equal to or higher than the dew point temperature.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a circulation device having a forced circulation device for forcibly circulating water in a bathtub and a combustion heating device for heating water in a circulation pipeline. A circulating water temperature measuring device for measuring a water temperature entering a forced circulation device, a flow rate calculating means for calculating an allowable maximum flow rate based on a value measured by the circulating water temperature measuring device, and a circulation line. A flow rate measuring means for measuring a flow rate in the inside, a flow rate varying means for varying a flow rate of water circulated by the forced circulation device, an allowable maximum flow rate calculated by the flow rate calculating means and measured by the flow rate measuring means. A flow rate appropriateness determining means for comparing the flow rate with the flow rate to determine the appropriateness of the flow rate, and a flow rate control means for controlling the flow rate variable means based on the flow rate appropriateness determining means to maintain the circulating water temperature at a predetermined temperature or higher. And equipped with.

[0007]

The forced circulating device of the circulating bath kettle control device of the present invention having such a configuration forcibly circulates water in the bathtub into the gas combustor. The circulating water temperature measuring device measures the water temperature entering the forced circulation device. Further, the flow rate calculating means calculates an allowable maximum flow rate based on the circulating water temperature measured by the circulating water temperature measuring device. Further, the flow rate measuring means measures the flow rate of the water circulated by the forced circulation device. In addition, the flow rate appropriateness determination means determines whether or not the measured flow rate measured by the flow rate measurement means is appropriate by comparing with the allowable maximum flow rate calculated by the flow rate calculation means. The flow rate varying means varies the flow rate circulated by the forced circulation device. Here, the flow rate control means controls the flow rate variable means based on the determination by the flow rate appropriateness determination means so as to maintain the circulating water temperature at or above the dew point temperature of the combustion gas. As a result, even when the water temperature is low in winter, it is possible to quickly maintain the water circulation outlet temperature at or above the predetermined temperature, so that the outer wall temperature of the heat exchange fins can be maintained at or above the dew point of the combustion gas, and the outer wall of a copper pipe or the like can be maintained. No water drops on the surface.

[0008]

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 bath adapter 45 is formed below the inner wall of the bathtub 24 to allow the water F to flow in and out. A return pipe 27 is provided at the center of the bus adapter 45.
Is connected. The return pipe 27 is connected to a pump 15 for circulating water. A pump drive circuit 32 for controlling the flow rate of the circulating water is connected to the pump 15. A circulating water temperature thermistor 26 for measuring 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. A flow rate sensor 33 for measuring the flow rate of the circulating water is mounted on a pipe in the middle of the pump 15 and the heat exchanger 50. The copper pipe 28 provided in the heat exchanger 50 has the same configuration as the conventional one, as shown in FIG. That is, the copper pipe 28
Are the lower pipes 41a, 41b, 41c, the middle pipe 4
2a, 42b and upper pipes 43a, 43b, 43c reciprocate 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, water F
Is 8 liters / min, and the bath water volume is 180 to 2
00 liters, gas combustion amount is about 12000 kcal /
how. Therefore, the water temperature rises about 19 degrees Celsius between entering and exiting the heat exchanger 50. The copper pipe 28 exiting the heat exchanger 50 is connected to an outgoing pipe 25 for returning circulating water to the bathtub. Outgoing pipe 25 is bus adapter 4
5 is connected to the outer periphery of the return pipe 27.

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 a configuration of a circulation type bath kettle control device according to the present embodiment. The controller 35, which is a main part of the control device, includes a CPU 36 for performing arithmetic processing, a ROM 37 for storing a control program, and a RAM 38 for temporarily storing data and the like. ROM37
Stores a flow rate variable program 48 for controlling the flow rate of the water F, a set flow rate calculation program 49 for calculating the set flow rate, and a flow rate propriety determination program 51. The controller 35 has a flow sensor 3 as an input.
3. The circulating water temperature thermistor 26 is connected. 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 are connected.

Next, the operation of the circulation bath controller having the above-described 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.

In winter, the temperature of the water F stored in the bathtub 24 is 0 to 10 degrees, and the temperature of the water F flowing to the return pipe 27 at the beginning is also the same. For example, when the case where the water temperature is 5 degrees is described, the temperature of the water F flowing into the lower pipe 41a of the copper pipe 28 is 5 degrees. The temperature of the flue gas immediately after the combustion of the propane gas G is about 1300 degrees, which is much higher than the dew point temperature of the flue gas (for example, 55 degrees). Therefore, the combustion exhaust gas of propane gas contains a large amount of water, but no water droplets are generated on the outer wall of the lower pipe.
The controller 35, which is a main part of the present invention, controls the heat exchanger 5 based on the measurement value of the flow rate sensor 33 which is fed back.
The flow rate of the water F is controlled so that the temperature of the water F flowing in the upper pipe 43c upstream from the outside to 0 does not become 40 degrees or less. In the circulating bath kettle of the present embodiment, by making the current flow rate equal to the set flow rate, the circulating water discharge temperature To can be maintained at 40 degrees or higher, so that the pipe outer wall temperature can be maintained at or above the dew point temperature of the combustion exhaust gas. Experiments have confirmed that there is no condensation.

The control method will be described with reference to the flowchart shown in FIG. RAM of controller 35
38, the circulating flow rate calculated by the set flow rate calculation program 49 is set (S2). Here, the set flow rate calculation program 49 is based on a relationship graph of the circulating flow rate and the circulating inlet water temperature shown in FIG. FIG. 13 is a graph in which the vertical axis indicates the circulating flow rate (liter / min) and the horizontal axis indicates the circulating water inlet temperature (degrees), and the curve shown in the graph is a circulating water outlet temperature curve. Therefore, if the circulating water temperature is known, the intersection of the circulating water temperature and the circulating water temperature curve is the allowable maximum circulation flow rate at the circulating water temperature.
In practice, the flow rate in the lower right part of the circulating water temperature curve at a circulating water temperature of 40 ° C. is such that the outer wall temperature of the pipe immediately before the copper pipe 28 exits the heat exchanger 50 is maintained at a dew point of 55 ° C. or more. Is determined.

When the circulating bath kettle is started to fire, the controller 35 measures the circulating water temperature Ti using the circulating water temperature thermistor 26 (S1). 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 5 degrees. Since the flow rate of the pump 15 at the beginning is the standard flow rate N, the current flow rate (S
3) is larger than the set flow rate (S4, No), the flow rate appropriateness determination program 51 determines, and based on this determination, the controller 35 lowers the rotation speed of the pump 15 via the pump drive circuit 32 by the flow rate variable program 48. The flow rate of the water F is reduced (S5). At this time, the rotation speed of the pump 15 is
The number of rotations corresponding to the circulating water temperature Ti is stored in the flow rate variable program 48 as a table, and is reduced according to the table. By reducing the circulation flow rate, the temperature of the water F flowing in the copper pipe 28 near the outlet of the heat exchanger 50 increases. Then, the rotation speed of the pump 15 is reduced until the current flow rate becomes lower than the set flow rate.

When the current flow rate becomes lower than the set flow rate by continuing the circulation heating (S4, Yes), the rotation speed of the pump 15 is increased (S6). Thereby, even if the water temperature is low in winter, the circulating water temperature To can be quickly maintained at 40 ° C. or higher, so that the outer wall temperature of the copper pipe 28 and the fins 21 can be maintained at the dew point temperature of the combustion exhaust gas or more, and the copper pipe No water droplets adhere to the outer walls of the fins 21 and the fins 21. Further, the copper pipe 28 and the fins are not corroded due to the dissolution of sulfur oxide or the like in the water droplets.

In this embodiment, the flow rate is controlled so that the circulating water temperature To is maintained at the set temperature Tc. However, the processing of step 4 is omitted, and the circulating water temperature To is reduced to the set temperature Tc.
Control may be performed as described above. Further, the upper and lower limit values may be set so that the circulating water 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 minimum temperature is set so that the outer wall temperature of the copper pipe 28 does not become lower than the dew point of the combustion exhaust gas. The maximum temperature is set so that the high-temperature water F does not flow out of the bus adapter 45. Providing the upper limit for the set temperature has an advantage that it is possible to prevent hot water from flowing out when a person enters the bathtub 24. Further, since the amount of circulating water is maintained at a predetermined value or less, there is an advantage that erosion (erosion of a wall surface by a water flow) can be prevented.

Next, a description will be given of a recirculating 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 water F flowing in the copper pipe 28, a flow control for controlling the flow rate between the pump 15 and the flow sensor 33 is performed. The point is that a water control valve 46 as a valve is provided. Water control valve 46
For example, by moving the valve body by a motor,
This is a flow control valve for flowing water F at an arbitrary flow rate by changing the gap between the valve seat and the valve element. In this case, the output of the pump 15 is fixed, and the flow rate of the water F flowing in the copper pipe 28 is controlled by the controller 35 by the flow rate control program.
The flow rate of the water control valve 46 is controlled via 7.

That is, as shown in FIG. 5, when the circulation type bath is started, the controller 35 measures the circulation water temperature Ti by the circulation water temperature thermistor 26 (S1).
1) The set flow rate is calculated by the set flow rate calculation program 49 based on the circulating water temperature Ti (S12). 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 5 degrees. Since the opening degree of the water control valve 46 is the standard flow rate N, the current flow rate (S13) measured by the flow rate sensor 33 is larger than the set flow rate (S14, N).
o) and the flow rate appropriateness determination program 51 makes a determination, and based on this determination, 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 flow rate variable program 48 (S15). ). At this time, the opening degree of the water control valve 46 is stored in the flow rate variable program 48 as a table corresponding to the circulating water temperature Ti, and is narrowed according to the table. By reducing the circulation flow rate, the copper pipe 2 near the outlet of the heat exchanger 50
The temperature of the water F flowing inside 8 rises.

Next, when the current flow rate becomes smaller than the set flow rate by continuing the circulation heating (S14, Ye).
s), the opening of the water control valve 46 is opened (S16). As a result, even when the water temperature is low in winter, the circulating water temperature To is quickly increased.
Can be maintained at 40 degrees or more, so the copper pipe 2
8 and the outer wall temperature of the fins 21 can be maintained at a temperature equal to or higher than the dew point temperature of the combustion exhaust gas, and water droplets do not adhere to the copper pipe 28 or the outer wall of the fins 21. Further, the copper pipe 28 and the fins are not corroded due to the dissolution of sulfur oxide or the like in the water droplets. According to the present embodiment, since the pump can be operated at a constant level as compared with the first embodiment, there is an advantage that control is facilitated.

Next, a description will be given of a recirculating bath kettle controller according to a third 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. The feature of the third embodiment is that, as shown in FIG. 8, a circulating water temperature thermistor 14 is provided at the outlet of the forced circulation device as a flow rate measuring means, the circulating water temperature To is measured, and the circulating water temperature thermistor 26 is used. The following equation 1 together with the circulating water inlet temperature Ti
Is that the current flow rate calculation program 52 for calculating the current flow rate Q of the water F flowing through the copper pipe 28 is stored in the ROM 37. Q = A / B Equation 1 where A = (Ip / 60) × η, B = To-Ti, I
p: gas input, η: thermal efficiency

That is, as shown in FIG. 7, when the circulation type bath is started, the controller 35 measures the circulation water temperature Ti by the circulation water temperature thermistor 26 (S2).
1) Based on the circulating water temperature Ti, the set flow rate is calculated by the set flow rate calculation program 49 (S22). Next, the circulating water temperature T is set by the circulating water temperature thermistor 14.
is measured (S23), and the current flow rate is calculated by the current flow rate calculation program 52 (S24). Here, as an example, consider a case in which a bath is heated by a circulating bath kettle from a state where the water temperature is 5 degrees. Since the flow rate of the pump 15 at the beginning is the standard flow rate N, the flow rate appropriateness determination program 50 determines that the current flow rate calculated from the equation 1 is larger than the set flow rate (S25, No). According to 48, the rotation speed of the pump 15 is reduced via the pump drive circuit 32 to reduce the flow rate of the water F (S26).
At this time, the number of rotations of the pump 15 is represented by a number of rotations corresponding to the circulating water temperature Ti as a table.
8 and are lowered according to the table. By reducing the circulation flow rate, the temperature of the water F flowing in the copper pipe 28 near the outlet of the heat exchanger 50 increases. And, until the current flow rate becomes lower than the set flow rate,
The rotation speed of the pump 15 is reduced.

When the current flow rate becomes lower than the set flow rate by continuing the circulating heating (S25, Yes), the rotation speed of the pump 15 is increased (S27). As a result, even when the water temperature is low in winter, the circulating water temperature To is quickly raised to 40.
Since the temperature of the copper pipe 28 and the fins 21 can be maintained at a temperature equal to or higher than the dew point temperature of the combustion exhaust gas, water droplets do not adhere to the outer walls of the copper pipe 28 and the fins 21. Further, the copper pipe 28 and the fins are not corroded due to the dissolution of sulfur oxide or the like in the water droplets.

Next, a description will be given of a circulation type bath kettle control device according to a fourth embodiment. Since the basic configuration and operation are the same as those of the circulation type bath kettle control devices of the second and third embodiments, only different points will be described, and description of the same parts will be omitted. The feature of the fourth embodiment is that, as shown in FIG. 10, a circulating water temperature thermistor 14 is provided at the outlet of the forced circulation device as a flow rate measuring means, the circulating water temperature To is measured, and the circulating water temperature thermistor 26 is measured. Circulating inlet water temperature T
The current flow rate calculation program 52 for calculating the current flow rate Q of the water F flowing in the copper pipe 28 from Equation 1 together with i
7 is provided with a water control valve 46 which is a flow control valve for controlling the flow rate at a position downstream of the pump 15 as a method of increasing or decreasing the flow rate of the water F flowing through the copper pipe 28.

That is, as shown in FIG. 9, when the circulation type bath is started, the controller 35 measures the circulation water temperature Ti by the circulation water temperature thermistor 26 (S3).
1) The set flow rate is calculated by the set flow rate calculation program 49 based on the circulating water temperature Ti (S32). Next, the circulating water temperature T is set by the circulating water temperature thermistor 14.
is measured (S33), and the current flow rate is calculated by the current flow rate calculation program 52 (S34). Here, as an example,
Consider a case where a bath is boiled by a circulating bath kettle from a state where the water temperature is 5 degrees. Since the opening of the water control valve 46 is the standard flow rate N at the beginning, the flow rate appropriateness determination program 50 determines that the current flow rate calculated from the equation 1 is larger than the set flow rate (S35, No), and based on this determination, the controller 35 Reduces the flow rate of the water F by reducing the opening of the water control valve 46 through the flow rate control circuit 47 by the flow rate variable program 48 (S3).
6). At this time, the opening degree of the water control valve 46 is stored in the flow rate variable program 48 as a table corresponding to the circulating water temperature Ti, and is narrowed according to the table. By reducing the circulation flow rate, the temperature of the water F flowing in the copper pipe 28 near the outlet of the heat exchanger 50 increases.

Next, when the current flow rate becomes smaller than the set flow rate by continuing the circulation heating (S35, Ye).
s) The opening of the water control valve 46 is opened (S37). As a result, even when the water temperature is low in winter, the circulating water temperature To is quickly increased.
Can be maintained at 40 degrees or more, so the copper pipe 2
8 and the outer wall temperature of the fins 21 can be maintained at a temperature equal to or higher than the dew point temperature of the combustion exhaust gas, and water droplets do not adhere to the copper pipe 28 or the outer wall of the fins 21. Further, since sulfur oxide and the like are not dissolved in water droplets to form sulfuric acid and the like, the copper pipe 28 is not eroded. Thereby, even if the water temperature is low in winter, the circulating water temperature To can be quickly maintained at 40 ° C. or higher, so that the outer wall temperature of the copper pipe 28 and the fins 21 can be maintained at the dew point temperature of the combustion exhaust gas or more, and the copper pipe 2
No water droplets adhere to the outer walls of the fins 8 and the fins 21. Further, the copper pipe 28 and the fins are not corroded due to the dissolution of sulfur oxide or the like in the water droplets. According to the present embodiment, since the pump can be operated at a constant level as compared with the third embodiment, there is an advantage that control is facilitated.

Next, a description will be given of a recirculating bath kettle controller according to a fifth 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. The feature of the fifth embodiment is that, as shown in FIG. 12, a positive displacement pump having both a flow rate measuring means for measuring a flow rate in a circulation pipe and a flow rate means for varying a flow rate of water circulated by a forced circulation device. 19, the current flow rate calculation program 53 for measuring the rotation speed N and calculating the current flow rate from the following equation 2 is RO
This is the point stored in M37. Q = K × N Equation 2 where K: constant N: pump rotation speed

That is, as shown in FIG. 11, when the circulating bath kettle is started, the controller 35 measures the circulating water temperature by the circulating water temperature thermistor 26 (S4).
1) The set flow rate is calculated by the set flow rate calculation program 49 based on the circulating water temperature Ti (S42). Next, the rotational speed of the positive displacement pump 19 is measured (S43), and the current flow rate is calculated from the current flow rate calculation program 53 (S43).
44). 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 5 degrees. Since the flow rate of the first displacement pump 19 is the standard flow rate N, the flow rate appropriateness determination program 50 determines that the current flow rate is larger than the set flow rate (S45, No), and based on this determination, the controller 35.
Is the pump drive circuit 32 by the flow rate variable program 48.
, The rotational speed of the positive displacement pump 19 is reduced to reduce the flow rate of the water F (S46). At this time, the rotational speed of the positive displacement pump 19 is stored in the flow rate variable program 48 as a table corresponding to the circulating water temperature Ti, and is lowered according to the table. By reducing the circulation flow rate, the temperature of the water F flowing in the copper pipe 28 near the outlet of the heat exchanger 50 increases. Then, the rotational speed of the positive displacement pump is reduced until the current flow rate becomes lower than the set flow rate.

When the current flow rate becomes larger than the set flow rate by continuing the circulating heating (S45, No), the rotation speed of the positive displacement pump 19 is reduced (S47). This allows
Even when the water temperature is low in winter, the circulating water temperature To is quickly increased to 4
Since the temperature can be maintained at 0 degrees or more, the outer wall temperature of the copper pipe 28 and the fins 21 can be maintained at a temperature equal to or higher than the dew point temperature of the combustion exhaust gas, and water droplets do not adhere to the outer walls of the copper pipe 28 and the fins 21. Further, the copper pipe 28 and the fins are not corroded due to the dissolution of sulfur oxide or the like in the water droplets. According to the present embodiment, the flow rate can be measured and the flow rate can be varied by one device, so that there is an advantage that the control becomes easier and the device can be simplified as compared with the other embodiments.

Although the present invention has been described with reference to several embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. That can be easily 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.

[0032]

As apparent from the above description, the circulating bath water heater control device of the present invention comprises a circulating water temperature measuring device for measuring the water temperature entering the forced circulation device, and a value measured by the circulating water temperature measuring device. Flow rate calculating means for calculating the allowable maximum flow rate from the flow rate, flow rate measuring means for measuring the flow rate in the circulation pipeline, flow rate appropriateness determining means for determining the appropriateness of the flow rate from the calculated flow rate and the measured flow rate, circulated by a forced circulation device Flow rate varying means for varying the circulating flow rate, and flow rate controlling means for controlling the flow rate varying means based on the flow rate propriety determining means to maintain the circulating water temperature at or above a predetermined temperature, so that when the water temperature is low in winter, Even from the start of the circulation bath, the circulating water temperature is quickly maintained from the beginning of the bath to a predetermined temperature or higher, and the outer wall temperature of the copper pipe and copper fins is set to the dew point temperature of the combustion exhaust gas or more. Prevents water droplets from adhering to the outer wall of the copper fins, nitrogen oxides and sulfur oxides in the combustion exhaust gas has an effect not to copper pipes and copper fins are corroded by dissolving in water droplets.

[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.

FIG. 7 is a diagram showing a configuration of a circulation type bath kettle control device according to a third embodiment.

FIG. 8 is a flowchart showing the operation of the circulation type bath kettle control device of the third embodiment.

FIG. 9 is a flowchart showing the operation of the circulation type bath kettle control device of the fourth embodiment.

FIG. 10 is a drawing showing a configuration of a circulation type bath kettle control device according to a fourth embodiment.

FIG. 11 is a flowchart showing the operation of the circulation type bath kettle control device of the fifth embodiment.

FIG. 12 is a drawing showing the configuration of a circulation type bath kettle control device according to a fifth embodiment.

FIG. 13 is a graph showing a relationship between a circulating flow rate and a circulating water temperature.

[Explanation of symbols]

 14 Circulating Outlet Temperature Thermistor 15 Pump 24 Bath 26 Circulating Inlet Temperature Thermistor 28 Copper Pipe 31 Gas Combustion Chamber 32 Pump Drive Circuit 33 Flow Rate Sensor 35 Controller 46 Water Control Valve 47 Flow Rate Control Circuit 48 Variable Flow Rate Program 49 Set Flow Rate Calculation Program 50 Heat Exchange vessel

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-2888641 (JP, A) JP-A-5-79702 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24H 1/00 602 F24H 1/10 302

Claims (1)

(57) [Claims] 1. A circulating bath-tank control device including a forced circulation device for forcibly circulating water in a bathtub and a combustion heating device for heating water in a circulation pipeline, wherein a temperature of water entering the forced circulation device is controlled. A circulating water temperature measuring instrument to measure, a flow rate calculating means for calculating an allowable maximum flow rate based on a value measured by the circulating water temperature measuring instrument, a flow rate measuring means for measuring a flow rate in a circulation pipe, and the forced circulation Flow rate varying means for varying the flow rate of water circulated by the apparatus; flow rate appropriateness determination for comparing the allowable maximum flow rate calculated by the flow rate calculation means with the flow rate measured by the flow rate measurement means to determine the appropriateness of the flow rate And a flow control means for controlling the flow variable means based on the flow appropriateness determination means to maintain the circulating water temperature at or above a predetermined temperature.