JPH06100366B2 - Freezing prevention device in hot water supply equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a hot water supply facility for circulating hot water in a heat radiating portion of a bathtub or a heater, and a circulation pipe or a circulation pump is frozen during the winter season or the like to cause device failure or damage. The present invention relates to an antifreezing device that can prevent the occurrence of frost.

<Prior art> As a freezing prevention device for hot water supply equipment, it has been conventionally used
There is a device described in Japanese Patent Publication No. -20843.

This device is equipped with a bypass circuit between the water supply side pipeline and the hot water outlet side pipeline of a water heater such as an instantaneous water heater, hot water storage boiler, etc., and a circulation pump that is driven by sensing the outside air temperature is installed in this bypass circuit. It is provided. When the outside air temperature falls below a certain level, the circulation pump is driven, whereby the water in the pipe circulates through the water heater, the hot water outlet side pipe, the bypass circuit, and the water supply side pipe line to prevent freezing.

<Problems to be Solved by the Invention> However, in the above-described conventional technology, since the circulation pump is driven regardless of the presence or absence of water in the pipeline, there are cases in which the pump is idle and wasteful. In addition to consuming a lot of electric power, there is a drawback that the durability of the circulation pump is deteriorated.

<Purpose> Therefore, an object of the present invention is to provide a freeze prevention device in a hot water supply facility in which the above-mentioned drawbacks of the prior art are solved, power consumption of the device is reduced, and durability is improved.

<Means for Solving Problems> The present invention allows hot water heated by a heat exchanger to be circulated to a heat radiating portion through a circulation pipe by a circulation pump, and when the outside air reaches a temperature below a certain temperature, a temperature switch A freezing prevention device in hot water supply equipment that operates the circulation pump to perform freezing prevention operation, wherein a water flow switch for detecting a water flow in the circulation pipe in addition to the temperature switch, and the circulation pump A voltage switching means for switching the drive voltage, and when the water flow switch detects a water flow, the circulation pump is driven in a normal freeze prevention operation, and when the water flow switch does not detect a water flow, The present invention is characterized in that a control unit for performing the antifreezing operation is provided by making the drive voltage of the circulation pump lower than that in the normal antifreezing operation.

<Operation> When neither the temperature switch nor the water flow switch is turned on, the controller performs a normal freeze prevention operation. If the water flow switch does not turn on even if the temperature switch is turned on, the controller uses the voltage switching means to switch the drive voltage of the circulation pump to a voltage lower than that in the normal freeze prevention operation, and the circulation pump is driven by the low voltage. Carry out anti-freezing operation while driving. The fact that the temperature switch is not turned on basically means that there is no water in the pipe, but it does not mean that there is no water in the pipe. If the water is choppy in the pipe or only in the circulation pump,
Or, if it happens that it takes time to send water, in these cases, if the circulation pump is not turned on just because the water flow switch is not turned on, the water remaining in the pipe or the circulation pump will be removed. It is liable to freeze, resulting in failure or damage. In the present invention, when the water flow switch is not turned on, the circulation pump is rotated at a voltage lower than that in the normal freeze prevention operation, so a failure due to unintentional freezing when seemingly there is no water, It is possible to avoid damage and save power in such a case. Of course, since the operation is performed at a low voltage, deterioration of the pump due to idle operation of the pump is prevented to some extent, and the durability of the device is increased. Also, the pump noise during idling is reduced.

<Embodiment> FIG. 1 is an overall configuration diagram of an embodying device when the present invention is applied to a bath heating device, and FIG. 2 is a flowchart showing an example of control of a circulation pump for preventing freezing.

As hot water supply equipment for the bathtub 10 which is a heat radiating portion, a bath kettle 20 which is a heat exchanger, a controller 30 thereof, a remote controller 40 and the like are provided. The bath kettle 20 is a hot water storage type water heater,
A fuel combustion unit 21, a hot water storage unit 22, a water inlet pipe 23, a hot water outlet pipe 24 and the like are provided. Between the bathtub 10 and the bath kettle 20 is a circulation path 2 including a forward pipe 25a, a return pipe 25b, and a heat exchange coil 25c.
5, a circulation pump 26 is provided in the outflow pipe 25a of the circulation path 25.
Is provided. The return pipe 25b is provided with a bath temperature detector 27, a bath water level detector 28, and a hopper 29 for supplying hot water from the hot water outlet pipe 24 to the bathtub 10.

The control unit 30 has a built-in microcomputer, for example, and has control software for hot water supply to the bathtub 10, reheating operation, warm water retention operation and automatic operation thereof, and control for freezing prevention. Software is embedded.

The remote controller 40 is an input device that gives a command for the user to take a bath. The remote controller 40 includes an automatic operation switch 41 for automatically performing warming and water retention from hot water supply to the bathtub 10 and heating, a reheating switch 42 for performing additional heating, and a heat retention for performing warming operation. A switch 43 is provided, and a hot water supply switch 44 for supplying hot water to the bathtub 10 and other places, a freeze prevention operation switch 45, a hot water temperature control knob 46, and the like are provided.

A water flow switch 51 is provided on the outflow pipe 25a of the circulation path 25, and a temperature switch 52 for detecting the outside air temperature is provided near the circulation pump 26. Further, the circulation pump 26 is provided with voltage switching means 53 for switching the drive voltage of the circulation pump.

To reheat the bath, the hot water heated by the heat exchange coil 25c is sent by the circulation pump 26 to the bathtub 10 through the outflow pipe 25a, and the hot water from the bathtub 10 passes through the return pipe 25b and the heat exchange coil 2
By being sent to 5c, the hot water is circulated in the circulation path 25 to be performed. The same applies to the warm-up operation. When retaining water,
Hot water from the hot water storage portion 22 of the bath kettle 20 passes through the hopper 29 and enters the bath tub 10.

Now, when the antifreeze operation switch 45 of the remote control unit 40 is turned on, when the temperature switch 52 detects outside air at a certain temperature or lower (for example, 3 ° C. or lower), the antifreeze operation is controlled via the control unit 30. If the main switch of the circulation pump 26 is turned on, and then the water flow switch 51 is also turned on (the water flow is detected), the circulation pump 26 is driven by the drive voltage for the normal antifreezing operation, and the water flow switch 51 If is off (does not detect water flow), the voltage switching means via the control unit 30
The drive voltage is switched to a low voltage at 53, and the circulation pump 26 is driven by the low drive voltage.

The drive voltage of the circulation pump 26 may be the same as or lower than the drive voltage for normal freeze prevention operation with respect to the drive voltage for bath heating. The actual value of each drive voltage is not particularly limited.

The invention is not limited to the embodiments described above. For example, it goes without saying that the case where the radiator of the heating device is replaced with the portion of the bathtub 10 in the above-described embodiment is also within the technical scope of the present invention.

<Effect> The present invention is configured as described above, and when the water flow switch does not detect the water flow during the anti-freezing operation, the circulation pump is operated normally (when the water flow switch detects the water flow) during the anti-freezing operation. Since the driving is performed at a lower driving voltage, even if it seems that there is no water, it is possible to avoid the failure and damage of the circulation pump and other parts due to the involuntary freezing. Of course, even in the case of the actual idle operation, the operation is switched to the low voltage operation, so that the energy saving is achieved, and the circulation pump is less damaged and has good durability. Further, it has an effect of reducing noise when the pump is idle.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodying device when the present invention is applied to a bath heating device, and FIG. 2 is a flowchart showing a control example of a circulation pump for preventing freezing. 10: Bathtub, 20: Bathtub 25: Circulation path, 26: Circulation pump 30: Control unit, 40: Remote control device 45: Freezing prevention operation switch 51: Water flow switch, 52: Temperature switch 53: Voltage switching means

Claims (1)

[Claims] 1. Hot water heated by a heat exchanger is circulated through a circulation pipe to a heat radiating section by a circulation pump, and when the outside air reaches a temperature below a certain level, a temperature switch operates to drive the circulation pump, A freeze prevention device for hot water supply equipment adapted to perform freeze prevention operation, comprising a water flow switch for detecting a water flow in the circulation pipe in addition to the temperature switch, and voltage switching means for switching the drive voltage of the circulation pump. If the water flow switch detects a water flow, the circulation pump is driven in a normal freeze prevention operation, and if the water flow switch does not detect a water flow, the drive voltage of the circulation pump is set to the normal voltage. An antifreezing device for hot water supply equipment, comprising a control unit for performing antifreezing operation at a lower temperature than during antifreezing operation.