JPH0641819B2 - After boiling prevention device for bath kettle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a post-boiling prevention device for a bath kettle, and more particularly to a post-boiling prevention device for operating a circulation pump for a certain period of time after completion of reheating. Therefore, the post-boiling can be surely prevented by optimizing the operating time of the circulation pump required for preventing the post-boiling.

[Prior Art and Problems Thereof] In a circulating superheat type bath kettle, there is residual heat in the heat exchanger portion at the end of reheating, and this residual heat causes a state of overheating in the heat exchanger, that is, a post-boiling state. Therefore, if the reheating operation is performed again within a certain time after the completion of the reheating, the overheated hot water is discharged into the bathtub, which is dangerous for the bather. Therefore, conventionally, the bath kettle is of a forced circulation heating type using a pump, and the pump for the forced circulation is idled for a certain period of time after completion of heating (only the pump is driven to put the heat exchanger in a non-heating state). Driving).
As a result, the heat exchange action continues for a certain period of time after the reheating is stopped, and the residual heat amount of the heat exchanger is transferred to the circulating water, the temperature of the heat exchanger matches the hot water temperature in the bathtub, and the post-boiling phenomenon is eliminated. It

However, in this conventional one, since the idle operation time is constant, the pump drive time after the end of reheating is often longer than necessary, and the drive noise of this pump is unpleasant at midnight. And there is much waste for that.

This is for the following reason.

The residual heat remaining in the heat exchanger after the reheating is stopped is proportional to the reheating time. Therefore, in order to reliably prevent the after-boiling phenomenon, it is necessary to set the idle operation time in conformity with the amount of remaining heat when the reheating time is the longest. If the idling time is set in this way, in the case of normal reheating that ends in a very short time, the amount of the remaining heat is small, so the pump drive will continue even after eliminating the after-boiling phenomenon. Because.

The present invention is such a "compulsory circulation heating type bath cooker in which a pump (P) for forced circulation is inserted in the circulation circuit (2) connecting the heat exchanger (1) and the bath (B). However, in the post-boiling prevention device for the bathtub, which is configured to continuously operate only the pump (P) for a predetermined time after the reheating is completed, the pump is
The task is to prevent noise and waste due to the operation time of (P) continuing more than necessary.

[Technical Means] The technical means of the present invention taken to solve the above-mentioned problem is "providing a time measuring means (3) for measuring the reheating time, and performing the operation in proportion to the output from the time measuring means (3). Calculation means (4) for setting the continuous operation time (T) of only the pump (P) after the end of heating
After the reheating, the pump (P) is operated continuously according to the output from the continuous operation time (T).
That is.

[Operation] The above technical means of the present invention operates as follows.

The continuous operation time (T) of the pump (P) after the end of reheating is set by the calculation means (4), and the pump (P) is set for this set time.
Operation continues. In this computing means (4), the continuous operation time (T) is determined by the output of the time measuring means (3) for measuring the time required for the reheating operation, and this set value is the output of the time measuring means (3). It will be proportional. Therefore, if the reheating time is long, the continuous operation time (T) is long, and conversely, if the reheating time is short, the continuous operation time (T) is
Is set short. That is, the continuous operation time (T) is set according to the residual heat amount of the heat exchanger (1).

[Effects] The present invention having the above-described configuration has the following unique effects.

Since the continuous operation time (T) is set according to the amount of heat remaining in the heat exchanger (1), the pump (P) cannot continue operating more than necessary when the reheating time is short, as in the conventional case. In addition, unnecessary operation of the pump (P) can be prevented, and the post-boiling phenomenon can be reliably prevented.

* Regarding the invention of claim 2 The invention of claim 2 uses the bathtub of the invention of claim 1 as a bathtub equipped with a heat retaining device. Since the continuous operation time (T) of the pump (P) will be set appropriately every time the heating operation is performed, the unnecessary operation of the pump (P) during the heat retention during which the reheating operation is repeatedly performed is eliminated, It is possible to prevent the inconvenience of taking a bath immediately after the warming operation, that is, the inconvenience of high-temperature hot water being discharged into the bath when the user takes a bath immediately after the warming operation and manually reheats it.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

In the bath kettle of this embodiment, the heat exchanger (1) in the body (K) and the heat exchanger (12) of the water heater are both housed, and the heat exchanger (1) and the bathtub (B A pump (P) is inserted in the circulation circuit (2) that connects the The hot water supply circuit of the heat exchanger (12) is branched and one of the hot water supply circuits (23) is connected to the circulation circuit (2) in order to enable the hot water supply to fill the bathtub (B). The hot water filling valve (22) is inserted in the hot water filling circuit (23).

The water filling operation via the water filling circuit (23) is controlled by the water level detector (21) that detects the water level in the bathtub (B), and when the water level in the bathtub (B) reaches the set water level. The filling operation is automatically stopped.

In addition, reheating by the heat exchanger (1) is performed by opening the gas valve (11) and burning the burner corresponding to the heat exchanger (1) and simultaneously operating the pump (P). , Bathtub (B)
The inside is circulated and heated, and the above-mentioned respective parts are brought into operation by the operation of the reheating switch (S ₁ ) provided on the remote control panel (6). Further, a water filling switch (S ₀ ) for performing the water filling operation is arranged on the remote control panel (6), and the output from each of these operation sections is provided in the control device (K). Each output is controlled based on the output from C).

Therefore, in this embodiment, a control circuit as shown in FIG. 3 is adopted, and in this circuit, the water filling switch (S ₀ ) is provided with a circuit for the water filling control and a circuit for the reheating control. Has been inserted into. The water filling switch (S ₀ ) also functions as a switch for automatic operation, and is always kept closed during operation of the appliance.

The water filling control circuit has a configuration in which a water level detector (21) is connected to the parallel circuit of the gas valve (13) and the water filling valve (22). The contact is opened when the water level reaches the set level in B).

The circuit for reheating control is the pump (P) and gas valve (11).
A reheating switch (S ₁ ) connected in series with a parallel circuit with
A timing means (3) for measuring the closing time of the reheating switch (S ₁ ) and a computing means (4) for computing the continuous operation time (T) by the output value of the timing means (3). , A timer (5) for setting the closing time of the output contact (51) to the continuous operation time (T) by the output from the computing means (4), and the output contact (51) is a hot water switch ( It is inserted between S ₀ ) and the pump (P), and the diode (53) is inserted between this output contact (51) and the pump (P).

The operation of this embodiment will be described below.

When the water filling switch (S ₀ ) is closed, the gas valve (13) opens and at the same time the water filling valve (22) opens, burning the burner of the heat exchanger (12) and heating hot water. It is supplied to the bathtub (B) through the water filling circuit (23) and the circulation circuit (2).

The water level in the bathtub (B) is monitored by the water level detector (21),
When this water level reaches the set water level, the water level detector (21) is opened and the filling operation is stopped. That is, the filling of water is completed and a predetermined amount of hot water is stored in the bathtub. Incidentally, since the hot water temperature at the time of this hot water filling is set to a predetermined value by a hot water temperature setting device (not shown), the hot water temperature in the bathtub (B) at the time when the hot water filling is completed also becomes the set hot water temperature. Will be set.

When bathing, if the hot water temperature in the bathtub (B) is low, it is reheated by operating the reheating switch (S ₁ ).

When the reheating switch (S ₁ ) is closed, the gas valve (11) is opened and the pump (P) is in the operating state.
The hot water in (B) is circulated and heated. Then, when the temperature in the bathtub (B) is raised to the desired temperature, the bather turns on the reheating switch.
(S ₁ ) is opened, the gas valve (11) is closed, and the reheating operation is stopped.

At this time, the time for which the reheating switch (S ₁ ) is closed is measured by the time counting means (3), and the signal input indicating that the reheating switch (S ₁ ) is opened and the time measurement are performed. The continuous operation time (T) is set in the calculating means (4) by the input value from the means (3). Incidentally, this calculation means (4)
Then, the output of the timing means (3) at the time when the output signal corresponding to the opening of the reheating switch (S ₁ ) is input is read, and the continuous operation time (T) is calculated based on this value.
The operation time of the timer (5) is set to the continuous operation time (T) by the output from the calculation means (4). As a result, the output contact (51) of the timer (5) is closed for the duration of the continuous operation time (T) after the time when the output from the computing means (4) is input. Therefore, the pump (P) has the output contact (51)
Conduction is made via and the operation is continued for the set time of the timer (5).

By this continuous operation, the residual heat of the heat exchanger (1) is transferred to the circulating water side and post-boiling is prevented.

The continuous operation time (T) is the reheating switch (S ₁ )
Is set so as to be proportional to the closing time (T ₁ ), and is set to a value given by the following equation in the calculating means (4), for example.

T = α (T ₁ ) (However, α = 1/12) Note that this calculation formula is a formula that sets the maximum value of the continuous operation time (T) to a constant value, and the reheating time is a fixed time or less. In this case, the formula may be such that the continuous operation time (T) changes proportionally.

In the above embodiment, the heat exchanger is used during the filling operation.
Although (1) is not heated, it can also be used in a bath kettle that circulates and heats the inside of the bathtub (B) to a set temperature by reheating after completion of filling.

In the case of a bath device having a heat retention function, the present invention can be adopted as a post-boiling prevention device after additional heating for heat retention operation.

Furthermore, it is possible to configure the control device (C) using a microcomputer. At this time, the central processing unit may execute the program according to the flowchart shown in FIG. 4, and the same operation as the control circuit shown in FIG. 3 is performed.

The post-boiling prevention device can also be adopted in a bathtub equipped with a heat retention device.In this type of bathtub, the pump (P) is used to keep the heat after the reheating operation is completed. It will be operated continuously according to the burning operation time.

A device provided with this heat retaining device may execute a control program according to the flowchart shown in FIG.

In addition, the heat retention device adopted in this embodiment is a temperature detection device inserted into the circulation circuit (2) at a constant standby time interval after a predetermined amount of hot water having a predetermined temperature is stored in the bathtub (heating state). The pump (P) is operated by means to detect the temperature of the hot water in the bathtub, and when the detected temperature (t _c ) falls below a set temperature (t ₀ ) below a certain level (for example, 1 ° C), reheating is performed. It is designed to keep the temperature inside the bathtub (B) at the set temperature. Therefore, the detected temperature (t _c )
Is below a certain level than the set temperature (t ₀ ), the reheating operation proceeds following the temperature detection operation,
When the temperature is not lower than a predetermined level than the set temperature (t ₀ ), the pump (P) is continuously operated until the reheating start condition is reached, and then the reheating operation is advanced.

When the post-boiling prevention device of the present invention is incorporated in a bathtub equipped with this type of heat retention device, a means for detecting the start time point of the reheating operation during heat retention and a means for detecting the end time point are required, and the former Timing means by output from detection means
(3) may be started, and the calculation by the calculation means may be performed by the output from the latter detection means. A means for detecting the opening / closing signal of the gas valve (11) can be adopted as the detecting means.

When the program based on the flowchart shown in Fig. 5 is executed under the conditions detailed above, the detected temperature (t
_{When c} ) becomes 1 ° C or less than the set temperature (t ₀ ), reheating is started, and the time after the start of reheating is measured by a time measuring means.
Measure by (3). Then, the temperature inside the bathtub (B) is the set temperature (t
_When the time becomes ₀ ), the reheating is stopped, the measurement of the reheating time by this time measuring means (3) is completed, and the continuous operation is performed in the same manner as in the case of FIG. 4 according to the output of this measured value. The time (T) is set, and the pump is pumped for this continuous operation time (T).
Pump (P) stops after (P) is continuously operated.

After that, after a certain waiting time, the hot water temperature detecting operation in the bathtub (B) for the warming operation is started, and the above operation is repeated during the warming.

The waiting time may be determined as a function of the reheating time (T ₁ ), and in this case, for example, the following equation can be adopted.

Standby time = (18.3 / T ₁ ) minutes + 10.1 minutes However, the reheating at the time of heat retention shall be reheated under the condition that the temperature drops by 0.6 ° C from the set temperature, and the tub procedure is 240 liters, combustion of the reheating burner This is an arithmetic expression when the amount is set to 10000 Kcal.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention, FIG. 2 is an overall explanatory diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of a control circuit used for the same, and FIG. 4 is a control program in the case of a microcomputer. Flowchart diagram, Fig. 5 is a flow chart diagram of a control program when a heat insulation device is provided. In the figure, (1) …… heat exchanger (B) …… tub (2) …… circulation circuit (P) …… Pump (3) …… Timekeeping means (4) …… Computing means

Claims (2)

[Claims] Claims: 1. A forced circulation heating type bath kettle in which a pump (P) for forced circulation is inserted in a circulation circuit (2) connecting the heat exchanger (1) and the bath (B). After the reheating, the pump
In the post-boiling prevention device for the bath kettle, in which only (P) is continuously operated for a predetermined time, a time counting means (3) for measuring the reheating time is provided, and is proportional to the output from this time counting means (3). Continuous operation time of the pump (P) only after finishing reheating
(T) setting means (4) is provided, after the reheating has been completed, the post-boil prevention device for the bathtub that allows the pump (P) to continue to operate according to the output from the continuous operation time (T) . 2. The after-boiling prevention device according to claim 1, wherein the bathtub is a bathtub with a heat retaining device.