JP3149012B2 - Circulation circuit freeze prevention device and circulation circuit inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circulation circuit for reheating, which is formed so as to circulate between a bathtub and an appliance body, and a circulation circuit for hot water heating, which is formed so as to circulate between a water heater and a radiator in a room. The present invention relates to an antifreezing device for preventing freezing of a circuit or the like.

[0002]

2. Description of the Related Art For example, a bath apparatus for reheating the inside of a bathtub has a configuration in which the bathtub and the heat exchanger for reheating are connected by a circulation circuit, and the circulation circuit detects the temperature of water in the circulation circuit. A water temperature sensor and a circulation pump are provided. In a bath apparatus installed in a cold region, an outside air temperature sensor is provided in order to prevent the inside of the circulation circuit from freezing in a cold winter season. That is, when the outside air temperature detected by the outside air temperature sensor becomes equal to or lower than a set temperature (a temperature at which freezing is likely to occur in the circulation circuit), the circulation pump is continuously operated to generate a water flow in the circulation circuit. To prevent freezing.

[0003] However, there is a case where there is no fear that the inside of the circulation circuit is immediately frozen even when the outside air temperature is lowered. For example, since the water retained in the circulation circuit is warm for a while after the reheating operation is stopped, the inside of the circuit does not freeze for a time (several hours) until the water drops to the freezing temperature. Therefore, in the above-described conventional device that performs the anti-freezing operation based on the outside air temperature, even if there is no fear of freezing in the circulation circuit, the operation of the circulation pump is performed when the outside air temperature is equal to or lower than the set temperature. In addition to wasteful power consumption, there is a problem of noise of the circulation pump. This problem occurs because the necessity of the antifreeze operation is determined based on the temperature of the water in the circulation circuit which is the antifreeze target.

In order to solve the above-mentioned problem, it is conceivable to directly detect the temperature of the water in the circulation circuit and perform anti-freezing control. That is, a water temperature sensor is attached to a portion of the circulation circuit formed in the main body case of the appliance body installed outdoors, which is most susceptible to the outside temperature, and the detected water temperature of the water temperature sensor is lower than the set temperature. Then, the circulation pump is operated.

[0005]

However, in the above-mentioned improvement, the temperature detected by a water temperature sensor provided in the appliance body is determined. Although the temperature of the exposed portion (not covered with the heat insulating material) is likely to be lower than the temperature of the portion where the water temperature sensor is provided, this temperature cannot be detected. Therefore, when the temperature detected by the water temperature sensor drops to the set temperature, the stagnant water in the vicinity of the exposed portion may already be frozen.

Although the above problem has been described by taking a bath apparatus as an example, a hot water heating apparatus having a circulation circuit formed so as to circulate between a radiator and a water heater installed outdoors. Also in this case, there is the same problem as in the case of the bath apparatus when trying to prevent the circulation circuit from freezing. Claim 1
The invention according to claim 2 has been made in view of the above-mentioned point, and is formed and circulated between a heat exchanger provided in a main body case, and the heat exchanger and a hot water supply target place. A device for preventing freezing of a circulating circuit including a pump and a water temperature sensor "is intended to more reliably prevent freezing of the circulating circuit.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, the invention according to claim 1 is based on the invention that "the water temperature in the circulation circuit detected by the water temperature sensor (confirmation of the corresponding part in the embodiment) or the outside temperature detected by the outside temperature sensor. Check operation timing determining means for outputting a check operation start signal when the temperature has dropped to the check reference temperature or when a predetermined time has elapsed since the circulation pump was stopped, and a check operation start signal from the check operation timing determining means And a water temperature sensor is continuously operated while the circulating pump driven by the check operation pump driving means is operated by operating the circulation pump until the check operation time elapses. A minimum temperature determining means for determining a minimum temperature in the detected water temperature, and an output of the minimum temperature determining means is lower than a reference water temperature. And is characterized in the check operation is time longer than setting a predetermined time only the circulation pump is provided an antifreeze mode pump drive means for maintaining the operating state "that the case.

According to the present invention, when the water temperature in the circulation circuit detected by the water temperature sensor or the outside air temperature detected by the outside air temperature sensor drops and falls below the check reference temperature, or for a predetermined time after the circulation pump is stopped. Has elapsed, the check operation timing determining means outputs a check operation start signal. Then, the check operation pump driving means is operated by the check operation start signal, and the accumulated water in the circulation circuit starts to circulate.

The output of the water temperature sensor is monitored by a minimum temperature judging means, which judges the lowest temperature among the water temperatures detected by the water temperature sensor during operation of the circulation pump. That is, the lowest temperature judging means judges the temperature of the water which is the coldest and has a high possibility of freezing out of all the water which has passed through the water temperature sensor arrangement portion in the circulation circuit.

Next, when the minimum temperature determined by the minimum temperature determination means is lower than the reference water temperature, the circulation pump is operated by the freeze prevention mode pump driving means for the freeze prevention time set to be longer than the check operation time. The condition is maintained, thereby preventing freezing of water in the circulation circuit.
When the circulating pump stops after the freezing prevention time has elapsed, the check operation timing determining means is operated again.

According to the first aspect of the present invention, while the circulating pump driven by the check driving pump driving means is operating, the lowest temperature in the water temperature continuously detected by the water temperature sensor is checked, and the lowest temperature is determined. When the temperature of the circulation pump is lower than the reference water temperature, the circulation pump is operated for a predetermined time (freezing prevention operation). The circulating pump may be operated for a predetermined time when the water temperature signal (not the minimum temperature) outputted by the controller becomes lower than the reference water temperature.

[0012]

As described above, according to the first and second aspects of the present invention, the antifreezing control is performed by judging the temperature of the water staying in the portion of the circulation circuit where the possibility of freezing is high. As a result, freezing of the circulation circuit can be reliably prevented. In particular, according to the second aspect of the present invention, a means for obtaining the lowest temperature among the temperatures detected by the water temperature sensor is not required, so that the control circuit can be simplified accordingly.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings. The circulation circuit (3) that circulates through the bath (1) and the heat exchanger (31) in the appliance body (2) has a circulation pump
(P), a water flow switch (37), a heat exchanger (31), and a water temperature sensor (30) are arranged in this order from the upstream side. Further, an outside air temperature sensor (21) is provided in a main body case (20) of the appliance main body (2) so as to easily detect an outside air temperature.

A gas valve (34) inserted in a gas circuit (33) to a gas burner (32) for heating the heat exchanger (31) is controlled by a control circuit (4) incorporating a microcomputer. Further, to the control circuit (4), outputs of the operating device (6) disposed on the bathroom wall surface, the water temperature sensor (30) described above, and furthermore, the outside air temperature sensor (21) are applied. Furthermore, a joint (11) is attached to a pair of bathtub pipes (11) (12) projecting from the bathtub (1).
0) The outgoing pipe (24) and the return pipe (25) are connected via (120), and the forward pipe (24) and the return pipe (25) are further connected to the joint (24).
0) It is connected to both ends of the water pipe (35) in the instrument body (2) via (250). And the above bathtub pipes (11) (12),
The outgoing pipe (24), the return pipe (25), and the water pipe (35) form the above-described circulation circuit (3) that connects the bathtub and the heat exchanger (31). In addition, the above bathtub pipes (11) (12), outgoing pipes (24), and return pipes (25)
Is styrene foam insulation (111) (121) (241) (251)
Surrounded by

In the above bath apparatus, when a turn-on signal of a reheating switch (61) provided in the operating device (6) is applied to the control circuit (4), an ignition device (not shown) is activated and the gas valve (3) is activated.
4) is opened, the gas burner (32) is maintained in a combustion state,
Further, the circulation pump (P) is operated. This allows
The bath water in the bathtub (1) flows in the order of bathtub pipe (12) → return pipe (25) → circulation pump (P) → water flow switch (37) → heat exchanger (31), and the heat exchanger (31). The heated water is heated in section 31), and the heated heated water is supplied to the outgoing pipe (24) → the bathtub pipe (11) → the bathtub.
The reheating cycle starts after flowing in the order of (1). And
When the temperature of the circulating water detected by the water temperature sensor (30) reaches the set temperature, the reheating operation stops.

[0016] The above-mentioned bath apparatus is provided with a circulation circuit in a cold winter season.
(3) It has a freezing prevention function to prevent the staying water in the inside from freezing. Therefore, the microcomputer incorporated in the control circuit (4) contains the freezing contents shown in the flowchart of FIG. Prevention program is stored. Hereinafter, the above-described freeze prevention control will be described with reference to the flowchart of FIG.

The outside air temperature detected by the outside air temperature sensor (21) is monitored in step (ST1). If the outside air temperature is lower than the check reference temperature (set to 3 ° C. in this embodiment), The control operation is shifted to step (ST2). And
In this embodiment, a step is taken to determine the outside air temperature.
The functional unit in the microcomputer that executes (ST1) corresponds to the check operation timing determination means described as the above-described invention specific matter. In this embodiment, the detected temperature of the outside air temperature sensor (21) is compared with the check reference temperature. However, the detected water temperature of the water temperature sensor (30) may be compared with the check reference temperature.

Next, in step (ST2), the water temperature detected by the water temperature sensor (30) is stored in the minimum water temperature memory (S0) and the initial water temperature memory (S1) of the microcomputer, while the timer (T1) Reset the circulating pump (P)
Activate Then, the bath water in the bathtub (1) is replaced by the bathtub pipe (12) → return pipe (25) → circulation pump (P) → water flow switch (37)
→ It flows through the circulation circuit (3) in the order of heat exchanger (31) → outgoing pipe (24) → bathtub pipe (11).

Next, in step (ST3), the water flow switch (37)
If the water flow detection signal is output, the measurement time of the timer (T1) is further determined in step (ST4). If the measurement time is less than 3 minutes, which is the check operation time, the flow proceeds to step (ST4). In (ST5), the detected temperature of the water temperature sensor (30) is compared with the water temperature stored in the minimum water temperature memory (S0), and if the former detected temperature is lower than the latter, the step (ST5) is performed.
In 6), the detected temperature is newly stored in the minimum water temperature memory (S0). Then, the operation of restoring the detected temperature of the water temperature sensor (30) that changes with time in the minimum water temperature memory (S0) is repeated until the above-described check operation time elapses. Then, by the time the check operation time elapses, the bathing water in the bathtub (1) goes around the circulation circuit (3), and the temperature detected by the water temperature sensor (30) during the above check operation time. Is stored in the minimum water temperature memory (S0). That is, bathtub (1)
→ bathtub pipe (12) → return pipe (25) → circulation pump (P) → water flow switch (37) → heat exchanger (31) → water temperature sensor (30) → outgoing pipe (24)
→ Retained water in the circulation circuit (3) connected to the bathtub pipe (11)
The temperature of the coldest water is stored in the lowest water temperature memory (S0).

Therefore, for example, the heat insulating material (251) of the return pipe (25), which is an external pipe connecting the appliance body (2) and the bathtub (1), is partially damaged and the part is exposed to expose the exposed part. When the staying water is most likely to freeze, the temperature of the water staying in the exposed portion is stored in the lowest water temperature memory (S0). In this embodiment, when the outside air temperature is lower than the check reference temperature of 3 ° C., the circulating pump is operated only for 3 minutes as the check operation time.
Control to continuously operate (P) (Step (ST1) (ST2)
The function unit in the microcomputer for executing (ST4)) corresponds to the check driving pump driving means of the first aspect of the present invention. A functional unit in the microcomputer for executing control (steps P (ST4) to (ST6)) for obtaining the minimum temperature of the water temperature detected by the water temperature sensor (30) during the operation of the circulation pump (P). 1 and 3 correspond to the lowest temperature determining means of the invention.

Next, when a check operation time of 3 minutes has elapsed since the operation of the circulation pump (P), the water temperature stored in the initial water temperature memory (S1) (the water temperature sensor (30) before the operation of the circulation pump (P)) is detected. ) And the temperature stored in the lowest water temperature memory (S0) (the lowest water temperature detected by the water temperature sensor (30) during operation of the circulation pump (P)). (Step 7) that the difference in temperature (Temperature) is larger than the normal temperature difference (K) is displayed on the display (65) of the operating device (6) to indicate that the insulation material (251) has peeled off. (See step (ST8)). That is, when there is a peeling portion of the heat insulating material (251), since the water temperature in the circuit corresponding to the peeling portion is the lowest, the temperature (the lowest water temperature memory (S0)
Temperature stored in the initial water temperature memory (S1) (water temperature sensor (30) before the circulation pump (P) is activated)
Temperature difference (base temperature), which is larger than the normal temperature difference (K), which makes it possible to determine that the heat insulating material (251) has peeled off, and displays this on the display (65). By doing so, the repair of the heat insulating material is called out. In the above-described embodiment, the basic temperature is controlled by the circulation pump.
(P) The water temperature detected by the water temperature sensor (30) before operation was used, but the average value of the temperature detected by the water temperature sensor (30) during operation of the circulation pump (P) and a predetermined value from the start of the circulation pump (P) The average value of the temperature detected by the water temperature sensor (30) within the time may be adopted as the basic temperature, and this basic temperature may be compared with the temperature in the minimum water temperature memory (S0). In this case, the respective average values and the like correspond to the basic temperature according to the third aspect of the present invention.

Next, the control operation proceeds to step (ST9), where the temperature stored in the minimum water temperature memory (S0) is compared with a reference water temperature (set to 0 ° C. in this embodiment). If the former temperature is lower than the latter reference water temperature, a waiting time of 60 minutes, which is a freezing prevention time, is executed in step (ST10). That is, the circulation pump (P)
Is maintained in operation to circulate the water in the circulation circuit (3), thereby preventing freezing in the circuit. After the time of 60 minutes elapses, after the circulation pump (P) is stopped in step (ST11), step
The control operation returns to the step (ST1).

In this embodiment, when the temperature stored in the minimum water temperature memory (S0) is lower than the reference water temperature of 0.degree. C., the circulation pump (P) is maintained in the operating state for 60 minutes as the antifreezing time. The functional units in the microcomputer that execute steps (ST9), (ST10), and (ST11) correspond to the antifreeze mode pump driving means according to the first aspect of the present invention. On the other hand, if the temperature stored in the minimum water temperature memory (S0) is higher than the reference water temperature as a result of executing the control in step (ST9), step (ST12) is executed. The outside air temperature detected by the outside air temperature sensor (21) is 0, which is the reference water temperature.
If the temperature is lower than ℃, the temperature detected by the water temperature sensor (30) is
It is determined in step (ST13) whether the temperature is lower than ° C.

The circulation pump (P) only for the above check operation time
Since the bath water in the bathtub (1) makes a circuit in the circulation circuit (3) after the operation of the water temperature sensor as described above, the temperature detected by the water temperature sensor (30) in this state is within the bathtub (1). Bath water temperature. Then, when the outside air temperature is determined to be 0 ° C. or more in step (ST12), or the temperature of the bathing water detected by the water temperature sensor (30) is 20 ° C. in step (ST13).
If it is determined that this is the case, there is no risk of the frozen water in the circulation circuit (3) being frozen early, so in such a case, stop the circulation pump (P) in step (ST14) and then Wait for 60 minutes in (ST15), then
The control operation returns to step (ST1).

On the other hand, if it is confirmed that the temperature of the bathing water detected by the water temperature sensor (30) is lower than 20 ° C. when the above-mentioned step (ST13) is executed, the accumulated water in the circulation circuit (3) is quickly reduced. In such a case, the control operation is shifted to step (ST10) because the possibility of freezing is high.
(P) is kept in operation for 60 minutes. Step (ST
If the water flow detection signal of the water flow switch (37) cannot be confirmed in step (ST3) even though the circulating pump (P) is operated in 2), it is determined that there is no remaining water in the circulation circuit (3). And stop the circulation pump (P).

Further, in the above-described embodiment, the case where the invention of the present application is implemented to prevent freezing of a bath apparatus has been exemplarily described. However, the present invention is designed to circulate between a radiator and a water heater installed outdoors. The present invention may be embodied as an antifreezing device for a hot water heating device having the formed circulation circuit. Further, in the above embodiment, it was determined whether or not the heat insulating material was damaged based on the temperature difference between the initial water temperature memory (S1) and the temperature stored in the lowest water temperature memory (S0), but the step (ST4) To (ST6), the temperature decrease amount is determined based on the temperature gradient when the temperature detected by the water temperature sensor (30) decreases and the duration of the temperature decrease phenomenon having the temperature gradient. The presence or absence of damage to the heat insulating material may be checked.

Further, the time from when the circulating pump (P) is operated in step (ST2) until the minimum temperature is detected, or when the circulating pump (P) is operated and stays at the place where the heat insulating material is damaged after being operated. Until the water passes through the water temperature sensor (30)
That is, the time until the water temperature sensor (30) detects the predetermined temperature gradient may be calculated so that the location where the heat insulating material is damaged may be specified.

In the above embodiment, the outside air temperature was compared with the check reference temperature in step (ST1).
In T1), the detected water temperature of the water temperature sensor (30) may be compared with the check reference temperature. In the above-described embodiment, the check reference temperature is set to 3 ° C., but if the check reference temperature is in the range of 2 ° C. to 7 ° C., it can be put to practical use.
In addition, the reference water temperature need not be 0 ° C as described above, and may be -1 ° C.
If it is in the range of ＋ １1 ° C., it can be practically used.

In the above embodiment, when it is determined that the outside air temperature is lower than 3 ° C. (step (ST1)), the circulating pump
Although (P) is operated only for the check operation time, instead of the determination of the outside air temperature, a wait of a predetermined time (for example, 20 minutes) may be executed as in step (ST1) of FIG. The control flowchart of FIG. 3 used in this case is different from the above-mentioned step (ST1) except that the control operation is returned to step (ST1) after stopping the circulation pump (P) in step (ST14). 2 is the same as that of FIG.

FIG. 4 is a control flowchart for explaining an embodiment of the present invention. This control flowchart also controls the bath apparatus having the structure shown in FIG. 1, and when it is detected in step (ST31) that the outside air temperature has fallen below the check reference temperature of 3 ° C., step (S31)
Activate the circulation pump (P) with T32) and the timer (T1)
Reset. If the temperature detected by the water temperature sensor (30) becomes 0 ° C. or less, which is the reference water temperature, before the time measured by the timer (T1) elapses the check operation time of 3 minutes, the step (S
At T36) (ST37), the circulating pump (P) is kept operating for 60 minutes. On the other hand, when the time measured by the timer (T1) exceeds 3 minutes, the control operation shifts from step (ST34) to step (ST38) (ST39), and the time of 60 minutes with the circulation pump (P) stopped is reached. Execute the wait.

In this embodiment, a step of monitoring the outside air temperature (ST31) and a step of operating the circulation pump (P) (S31)
The function unit in the microcomputer that executes T32) corresponds to the check operation timing determination means and the check operation pump driving means of the invention of claim 2 respectively. or,
If the temperature detected by the water temperature sensor (30) is lower than 0 ° C, a step (S) is performed to maintain the circulation pump (P) in the operating state for only 60 minutes.
The functional unit in the microcomputer which executes T36 and ST37 corresponds to the antifreeze mode pump driving means of the second aspect of the present invention.

In the embodiment shown in FIG. 4, the circulating pump (P) is operated when it is determined that the outside air temperature is lower than 3 ° C. (step (ST31)). hand,
Waiting for a predetermined time (for example, 20 minutes) may be executed. In step (ST31), the water temperature detected by the water temperature sensor (30) may be compared with a check reference temperature (3 ° C.).

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a bath apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a first control program used for an antifreezing operation of the bath apparatus of FIG. 1;

FIG. 3 is a flowchart illustrating a second control program used for the freeze prevention operation of the bath apparatus of FIG. 1;

FIG. 4 is a flowchart illustrating a third control program used for the freeze prevention operation of the bath apparatus of FIG. 1;

[Explanation of symbols]

 (1) ... bathtub (2) ... instrument body (3) ... circulation circuit (4) ... control circuit (6) ... operating device (30) ... water temperature sensor (31) ···Heat exchanger

Claims (3)

(57) [Claims] A heat exchanger disposed in a main body case; and a freeze prevention device for a circulation circuit formed to circulate between the heat exchanger and a hot water supply target and including a circulation pump and a water temperature sensor. Check that the check operation start signal is output when the water temperature in the circulation circuit detected by the water temperature sensor or the outside temperature detected by the outside air temperature sensor drops to the check reference temperature or when a predetermined time has elapsed since the circulation pump stopped. An operation timing determination unit, a check operation pump drive unit that is operated by a check operation start signal from the check operation timing determination unit and operates a circulation pump until a check operation time elapses, and the check operation pump drive unit. While the driven circulating pump is operating, the water temperature sensor A lowest temperature determining means for obtaining a low temperature; and a pump drive for an antifreeze mode for maintaining a circulating pump in an operating state for a predetermined time set longer than the check operation time when an output of the lowest temperature determining means is lower than a reference water temperature. Means for preventing freezing of a circulation circuit. 2. An apparatus for preventing freezing of a circulation circuit, which is provided in a main body case, and which is formed so as to circulate between the heat exchanger and a hot water supply target and includes a circulation pump and a water temperature sensor, Check that the check operation start signal is output when the water temperature in the circulation circuit detected by the water temperature sensor or the outside temperature detected by the outside air temperature sensor drops to the check reference temperature or when a predetermined time has elapsed since the circulation pump stopped. An operation timing determination unit, a check operation pump drive unit that is operated by a check operation start signal from the check operation timing determination unit and operates a circulation pump until a check operation time elapses, and the check operation pump drive unit. A water temperature signal continuously output by the water temperature sensor while the driven circulation pump is operating An anti-freeze mode pump driving means for maintaining the circulating pump in an operating state for a predetermined time longer than the check operation time when the water temperature becomes lower than a reference water temperature; . 3. A water temperature sensor and a circulation pump provided in a circulation circuit covered with a heat insulating material, and a lowest temperature among temperatures continuously detected by the water temperature sensor while the circulation pump is operating. A circulating means for determining that the heat insulating material has been peeled off when a difference between a basic temperature such as a temperature detected by the water temperature sensor before the operation of the circulating pump and the minimum temperature is larger than a normal temperature difference; Circuit inspection equipment.