JP2001248897A - Bath circulation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption and noise of a circulation pump. SOLUTION: A function for calculating a circulated flow amount of a circulation pump 18 and a function for adjusting circulation capability of it are provided based on an applied heating value and a temperature difference detected with thermisters 19 and 20 provided on both forward and backward sides of a bath circulation circuit 4. Thus, depending on a bathtub and bath piping construction conditions, the capability of the bath circulation pump 18 is adjusted for driving at an appropriate capability, resulting in reduced wasteful power consumption and noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water circulating device for a water heater provided with a function of automatically pouring and maintaining hot water of a predetermined temperature and amount in a bath tub and for circulating the hot water in the bath tub by means of a pump. More particularly, the present invention relates to a method for controlling the capacity of a circulation pump in a circulation circuit.

[0002]

2. Description of the Related Art Conventionally, this type of water heater has a structure as shown in FIG. 2. Description of the Related Art An automatic hot water filling function for automatically pouring hot water having a predetermined temperature and water amount into a bathtub via a bypass circuit from a hot water supply circuit for heating water from a water supply pipe through a bypass circuit has begun to spread. This automatic hot water filling function also has a function to keep the temperature of the bath tub after pouring constant, and forcibly detects the hot water of the bath tub by pumping the hot water of the bath tub,
When the temperature of the hot water is lower than a set value, a bath having a bath circulation circuit for reheating and returning the bath to a bathtub is becoming widespread.
The structure and function will be briefly described below with reference to the drawings.

FIG. 3 is a structural diagram showing an example of a water heater having a conventional bath circulation circuit. As shown in the figure, the water heater 1 is largely composed of a hot water supply circuit 2, a bypass circuit 3, a bath circulation circuit 4, a control circuit 5 for connecting and controlling functional components and sensors of those circuits by signal lines, and a main body of the water heater 1. Is a remote control 6 for operating the water heater at a remote location
Is provided. A circulation pipe 7a and a return pipe 7b are connected to the bathtub 8 via a bath adapter 9 from the main body of the water heater 1, and the hot water boiled in the water heater 1 is poured into the bathtub 8.

[0004] The hot water supply circuit 2 has a hot water supply burner 12 for heating the supplied water and a hot water supply heat exchanger 11, and a water supply pipe 10 provided with a water quantity sensor 22 for measuring an inflow amount from city water is connected to the hot water supply heat exchanger. 11 and a hot water supply pipe 13. The bypass circuit 3 is connected to the hot water supply pipe 13, and the bypass pipe 15 provided with the hot water supply electromagnetic valve 14 guides the hot water heated in the hot water supply circuit 2 to the bath circulation circuit 4. The bath circulation circuit 4 has a bath burner 16 and a bath heat exchanger 17 for reheating and driving out the circulated water in the bathtub 8, and a forward circulation connecting the bath heat exchanger 17 to the bath circulation adapter 9 of the bathtub 8. It comprises a pipe 7a, a return circulation pipe 7b connected from the bath circulation adapter 9 to the circulation pump 18 and the bath heat exchanger 16. A forward thermistor 19 for measuring the temperature of hot water reheated and driven out by the bath heat exchanger 17 is provided on the outgoing circulation pipe 7a, and a return thermistor 20 for measuring the temperature of hot water returned from the bathtub 8 into the circuit is provided on the return circulation pipe 7b. And a flow switch 21 for circulating determination which is turned on and off by a circulating flow in the circuit.

The control circuit 5 includes a microcomputer, and has an arithmetic circuit 24 for performing an arithmetic operation based on signals from sensors such as a going thermistor 19, a return thermistor 20, a flow switch 21 and the like.
The operation of the water heater 1 is performed upon receiving an operation instruction signal from the remote controller 6.

Here, the above-mentioned automatic hot water beam function will be briefly described. Automatic hot water switch 23 of remote control 6
Is pressed, the control circuit 5 sets the pouring solenoid valve 1 of the bypass circuit 3
Open 4. Then, water is supplied to the hot water supply circuit 2 and the water supply pipe 1
The hot water supply burner 12 is ignited and the supplied water is supplied to the hot water supply heat exchanger 11.
Heated in hot water. Then, the hot water is supplied to the bath circulation circuit 4 via the bypass pipe 15 by the hot water supply pipe 13, passed through the going circulation pipe 7 a and the return circulation pipe 7 b, and poured into the bathtub 8 from the bath adapter 9 attached to the bathtub 8.

The amount of pouring is set in advance. At first, a certain small amount (for example, 10 l) of the bathtub 8 in which the water level is lower than the bath adapter 9 is poured. Next, pouring solenoid valve 1
4 is closed, the circulating pump 18 is operated, and the flow switch 21 is used to check whether there is residual hot water in the bathtub 8. If it is determined that the flow switch 21 does not operate and there is no remaining hot water, the pouring solenoid valve 14 is opened again to perform pouring up to a preset hot water amount. At this time, the water amount sensor 22 accumulates the pouring amount, and the control circuit 5 closes the pouring electromagnetic valve 14 when the pouring amount reaches a preset pouring amount.

When the pouring is completed, the circulating pump 18 of the bath circulation circuit 4 rotates, the flow switch 21 for circulating determination is operated, and it is confirmed that the hot water has been poured into the bathtub 8. Then, the hot water in the bathtub 8 is taken into the bath circulation circuit 4 through the return circulation pipe 7b, and the temperature of the hot water in the bath 8 is measured by the thermistor 20. If the hot water temperature is lower than the set temperature, the bath burner 16 is ignited and the bath heat exchanger 17 is passed through the bathtub 8.
The hot water is reheated and driven out and returned to the bathtub 8 from the circulation pipe 7a. The control circuit 5 measures the temperature of the hot water in the bathtub 8 with the return thermistor 20 and circulates the hot water until the hot water reaches the set value.
Perform reheating. Even after boiling, every predetermined time (for example, 1
At 0 minute intervals), a circulation check of the hot water temperature is performed to keep the temperature at the set hot water temperature.

On the other hand, after the first fixed small amount of molten metal is poured, the circulating pump 18 is operated, the flow switch 21 is operated, and the bathtub 8 is turned on.
If it is determined that there is remaining hot water, reheating is performed for a certain period of time, and the remaining hot water amount is calculated from the temperature difference between the outgoing thermistor 19 and the return thermistor 20. Then, the insufficient amount of hot water is poured into the set hot water amount, and the circulation pump 18 is operated again in the same manner as in the case of no remaining hot water, and the hot water is circulated until it reaches the set value.
Perform reheating.

[0010]

However, since the capacity of the conventional circulation pump of the bath circulation circuit is not variable, the distance from the water heater main body to the bathtub is long and the length of the bath piping is long, or the bathtub is difficult to use. When installed in a place higher than the water heater body, the load of the circulating pump will match the large conditions,
Regardless of the construction conditions, it was necessary to set the circulation pump to always operate at the maximum capacity.

Therefore, even when the bath pipe is short and the load of the circulation pump is small, the circulation pump operates at the maximum capacity,
There was a problem that the power consumption and noise of the pump became higher than necessary.

[0012]

According to the present invention, there is provided a bath circulating apparatus comprising: a thermistor provided on an outgoing side and a return side of a bath circulating circuit; and a heat quantity given to hot and cold water passing through the bath circulating circuit by a bath heat exchanger. An arithmetic circuit for calculating and storing the circulating flow rate of the circulating pump based on the difference between the detected temperature of the hot water and the returning hot water determined by the thermistor, and an adjusting circuit for adjusting the driving capacity of the circulating pump. .

According to the above invention, the capacity of the circulation pump of the bath circulation circuit can be adjusted in accordance with the bathtub and bath piping construction conditions, the pump can be operated at an appropriate capacity to prevent wasteful power consumption of the pump, and the pump can be operated at an appropriate capacity. Noise can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bath circulating apparatus according to claim 1 of the present invention comprises a bath tub and a bath circulating circuit for taking out hot water from the bath tub.
A circulating pump for circulating hot and cold water in the bathtub through the bath circulation circuit, a bath heat exchanger for heating the hot water in the bath circulation circuit, a thermistor provided on the forward and return sides of the bath circulation circuit, An arithmetic circuit for calculating and storing the circulating flow rate of the circulating pump from the amount of heat given to the hot and cold water passing through the bath circulation circuit from the exchanger and the difference between the detected hot and cold hot and cold water temperatures obtained by the thermistor; and And an adjusting circuit for adjusting the driving capacity of the circulating pump based on the circulating flow rate thus obtained.

Then, according to the bathtub and bath piping construction conditions,
The capacity of the circulation pump in the bath circulation circuit can be adjusted, and the pump can be operated with an appropriate capacity to prevent wasteful power consumption of the pump and reduce the noise of the pump.

Further, the bath circulation device according to the second aspect of the present invention is provided with an adjustment circuit for performing PWM control by using the circulation pump as a DC pump. According to the present invention, the capacity of the circulation pump of the bath circulation circuit can be adjusted at a low voltage.

Further, the bath circulating apparatus according to a third aspect of the present invention has a circuit for determining that the circulating pump is running idle when a current of a predetermined value or more continuously flows through the circulating pump for a predetermined time or more. I have. According to the present invention, when there is no hot water in the bathtub and the circulation pump runs idle, the idle operation of the circulation pump can be detected.

Further, the bath circulation device according to the fourth aspect is characterized in that when it is determined that the circulation pump is running idle, the operation of the circulation pump is stopped.

According to the present invention, noise due to idling of the circulation pump and seizure of the pump can be prevented.

Further, in the bath circulation device according to the fifth aspect, when the circulation pump starts operation, the rotation of the pump is once performed at a predetermined low speed for a predetermined time, and then the rotation is increased to a high speed at a predetermined time. Features.

Furthermore, in the bath circulation device according to the present invention, when the operation of the circulation pump is stopped, the rotation of the pump is once decreased from the high-speed rotation to a predetermined low-speed rotation, and then the rotation is performed at a low speed for a predetermined time and then stopped. It is characterized by things.

According to these, it is possible to prevent a water hammer phenomenon that occurs when the circulation pump is started and stopped.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a structural view showing an example of a water heater provided with a bath circulation circuit according to the present invention. The difference from the conventional example is that a capacity adjusting circuit 25 of the bath circulation pump is added to the control circuit 5, and other parts having the same structure are assigned the same reference numerals and detailed description thereof is omitted. The capacity adjusting circuit 25 is an electric circuit that adjusts the bath circulation pump 17 determined by the arithmetic circuit 24 of the control circuit 5 to operate at an optimum capacity. The circulation pump 18 is a DC pump and the capacity adjustment circuit 25 is a PWM control (Pulse Wi-Fi).
The capacity of the circulation pump 18 is controlled by modulating the pulse width of the current with dthModulation).

Circuit 2 for adjusting the capacity of the circulation pump of this water heater
1 and FIG. 2 from the time of test operation, which is the first operation.
This will be described with reference to the operation sequence diagram of FIG.

At the time of the test operation, first, after the inside of the bathtub 8 is emptied, the plug is surely plugged, and when the test run switch on the control circuit 5 is pressed (S1), the bathtub 8 is automatically charged into the bathtub 8 at a constant temperature and a fixed amount V (for example, 100 l) of hot water is poured (S2). Circulation pump 17 is adjusted to operate at half its maximum operating capacity. After pouring into the bath 8, the circulation pump 17 is operated to take the hot water in the bath 8 into the bath circulation circuit 4 from the return circulation pipe 7 b and the forward circulation pipe 7 a, and the bath heat exchanger 17 returns the thermistor 20 to a certain temperature. Reheat until a rise ΔT (deg) is detected. During this reheating, the temperature difference ΔTup (deg) detected by the going thermistor 19 and the return thermistor 20 at regular intervals and the time t (min) required for reheating are also measured and stored. (S3). The arithmetic circuit uses these results to determine the actual initial circulation flow rate Qx (l / min) of the bath circulation circuit by the following equation.

Qx = V × ΔT / (ΔTup
Avr × t) (However, ΔTupAvr (deg): average value of ΔTup (deg)) Here, the capacity adjustment circuit 25 determines the optimal target circulation flow rate Qi (for example, 7 l / min) of the pump stored in advance. A comparison is made with the initial circulation flow rate Qx (S4).

If the result of the determination is Qx> Qi, that is, if the circulating flow rate is greater than the target circulating flow rate, the circulating pump operating capacity is reduced by a predetermined amount (for example, 10% of the pump) (S
5) As described above, the reheating / expulsion is performed to measure the temperature rise ΔT, the detected temperature difference ΔTup, and the reheating time t, and the calculation of the circulation flow rate is repeated (from S3 to S4) to circulate the target pump. Reduce to flow value Qi.

On the other hand, if the result of the determination is Qx <Qi, that is, if the circulating flow rate is smaller than the target circulating flow rate, the circulating pump operating capacity is increased by a predetermined amount (for example, 10% of the pump) in the same manner as described above ( S6). At this time, it is determined whether the maximum operation capacity of the pump is exceeded (S7).
If the maximum operation capacity of the pump is exceeded, an error display is displayed on the remote controller 6 assuming that the construction conditions of the bathtub 8 and the circulation pipes 7a and 7b exceed the capacity of the circulation pump 17 (S8).

Finally, it is confirmed that the operating capacity of the circulating pump 18 has reached the target circulating flow rate value Qi, and the operating capacity of the circulating pump 18 at that time is stored in the ROM in the arithmetic circuit 5.
(Electrically rewritable read-only memory)
9), end the pump capacity adjustment and test run (S1)
0).

Next, a method for controlling the capacity of the circulation pump 18 will be specifically described. The circulation pump 18 is a DC pump driven by a DC power supply, and the capacity adjustment circuit 25 performs PWM control for adjusting the capacity of the circulation pump 18 by modulating the duty ratio of the ON / OFF signal of the pulse. Since the PWM control can be performed at a relatively low voltage, it is preferable in terms of safety when hot water from a water heater or the like is used and there is a possibility of electric shock.

Further, since the circulating pump is a DC pump driven by a DC power supply, when hot water runs out in the bathtub 8 and the bath circulation circuit 4 and the circulating pump 17 runs idle, the current value of the pump increases. The control circuit 5 monitors the current value flowing to the circulation pump, and when the current value of the predetermined value or more continuously flows through the circulation pump 18 for the predetermined time or more, it is possible to determine that the circulation pump is idling. it can.

When it is determined that the circulating pump 18 is idling, the operation of the circulating pump 18 is stopped, so that noise due to idling of the circulating pump 18 and burn-in of the pump can be prevented.

When the operation of the circulation pump 18 is started, control is performed such that the rotation of the circulation pump 18 is once performed at a predetermined low speed for a predetermined time and then is increased to a high speed for a predetermined time. When the operation of the circulation pump 18 is stopped, the rotation of the circulation pump 18 is temporarily lowered from the high-speed rotation to a predetermined low-speed rotation, and is then stopped at a low-speed for a predetermined time and then stopped. Therefore, the water hammer phenomenon that occurs in the bath circulation circuit 4 when the circulation pump 18 is started and stopped can be prevented, and the sealing property and durability in the circulation circuit 4 can be improved.

[0035]

As is apparent from the above description, the following effects can be obtained according to the bath circulation device of the present invention.

(1) The circulation flow rate of the circulation pump is calculated from the amount of heat applied to the hot and cold water passing through the bath circulation circuit and the difference between the detected temperature of the forward and return hot water from the thermistor provided in the bath circulation circuit. It is equipped with an adjustment circuit that memorizes and adjusts the driving capacity of the circulation pump.In order to adjust the capacity of the circulation pump of the bath circulation circuit according to the bathtub and bath pipe construction conditions, It can be operated to prevent wasteful power consumption and reduce noise.

(2) PW using a circulating pump as a DC pump
Since the M control is performed, the capacity of the bath circulation pump can be adjusted at a low voltage.

(3) Since the circuit has a circuit for judging and stopping the idling operation by detecting that the current value of the DC pump becomes large when the circulating pump is idling, the idling operation of the circulating pump is performed. Noise and seizing of the pump can be prevented.

(4) When the circulating pump starts operating, the pump rotates once at a predetermined low speed for a predetermined time and then rises to a high speed. When the circulating pump stops operating, the pump rotates from the high speed. Once the rotation speed is lowered to a predetermined low speed, the rotation is performed at a low speed for a predetermined time and then stopped. Therefore, it is possible to prevent a water hammer phenomenon occurring in the bath circulation circuit when starting and stopping the circulation pump.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a bath circulation device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of a circulating pump capacity adjusting circuit of the apparatus.

FIG. 3 is a configuration diagram of a conventional bath circulation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot-water heater main body 4 Bath circulation circuit 5 Control circuit 7a Outgoing circulation pipe 7b Return circulation pipe 8 Bathtub 18 Circulation pump 19 Outgoing thermistor 20 Return thermistor 24 Arithmetic circuit 25 Capacity adjustment circuit

Claims (6)

[Claims] 1. A bath tub, a bath circulation circuit for taking out the bath water, a circulation pump for circulating the bath water through the bath circulation circuit, a bath heat exchanger for heating the bath water in the bath circulation circuit, and the bath. Thermistors provided on the outgoing and return sides of the circulation circuit, and the amount of heat applied to the hot and cold water passing through the bath circulation circuit from the bath heat exchanger and the detected temperature difference between the forward and return hot water determined by the thermistor. A bath circulating apparatus comprising: an arithmetic circuit for calculating and storing a circulating flow rate of a circulating pump; and an adjusting circuit for adjusting the driving capacity of the circulating pump based on the circulating flow rate obtained by the arithmetic circuit. 2. The apparatus according to claim 1, wherein the circulation pump is a DC pump, and a circuit for performing PWM control and adjusting the capacity of the circulation pump is provided. 3. The bath circulating apparatus according to claim 2, wherein it is determined that said circulating pump is running idle when a current value of a predetermined value or more continuously flows through said circulating pump for a predetermined time or more. 4. The apparatus according to claim 3, wherein the operation of the circulation pump is stopped when it is determined that the circulation pump is running idle. 5. When the circulating pump starts operating, the circulating pump rotates once for a predetermined time at a predetermined low speed and then rises to a high speed for a predetermined time.
The bath circulation device as described. 6. The apparatus according to claim 1, wherein when the operation of the circulating pump is stopped, the rotation of the circulating pump is once lowered from a high-speed rotation to a predetermined low-speed rotation, and then is rotated at a low speed for a predetermined time and then stopped. .