JP2004044297A - Power-saving antifreezing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-saving antifreezing device which prevents freezing accidents while reducing useless energization of the device to the utmost. <P>SOLUTION: A heater 2 of the antifreezing device is arranged so as to heat a pipe when energized. Then an energization control section 9 starts energization of a heating section if a detection temperature of a pipe temperature sensor 3 is equal to or below an energization starting temperature, terminates the energization of the heating section if the detection temperature is equal to or above an energization terminating temperature, and raises at least one of the set energization starting temperature and the set energization terminating temperature if a period of time elapsed from the preceding energization termination to the subsequent energization starting is equal to or below a predetermined value. Further the antifreezing device may be provided with an ambient temperature sensor 9f in addition to the sensor 3, and therefore power is saved by further finely setting control conditions, based on the ambient temperature. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power-saving type anti-freezing device, and more particularly, to a power-saving type anti-freezing device that prevents freezing of a water distribution pipe or the like by an electric heater in a cold region or the like.
[0002]
[Prior art]
BACKGROUND ART Conventionally, in order to prevent a water pipe or the like from freezing in a cold region, it has been practiced to wind the water pipe with an anti-freeze band formed of a flat cord-like electric heater to prevent freezing.
[0003]
A conventional anti-freezing device attaches a thermal reed switch or thermo switch to a water pipe to detect the temperature of the water pipe, and when the detected temperature falls below 6 ° C., for example, starts energizing the anti-freezing zone, and when the temperature rises above 12 ° C. The operation for stopping the energization is set to be repeated. With this setting, it is possible to prevent the water pipe from freezing even when a cold wave, for example, where the outside air temperature drops to −20 ° C., strikes.
[0004]
[Problems to be solved by the invention]
By the way, the reason why the operating temperature is set higher as described above is to start the energization as soon as possible in consideration of safety before a water pipe such as a water pipe freezes.
[0005]
However, if the operating temperature is set high and the water pipe is heated early to prevent freezing, the problem of heating the water pipe even when freezing does not occur cannot be avoided, and the power consumption increases. is there.
[0006]
In order to solve the above problem, for example, when the outside air temperature is detected, and when the outside air temperature is equal to or higher than a predetermined temperature, the power is shut off, and the thermal reed switch, the thermoswitch, etc. are turned on and the anti-freezing zone is not energized. In some cases, this can lower the duty ratio and save power.
[0007]
However, this method ignores the actual pipe temperature and lowers the electrical conductivity, so that if the outside air temperature measurement site is not appropriate, the pipe may be overheated or frozen.
[0008]
The present invention has been made in view of the above problems, and sets the energization start temperature and the energization stop temperature as low as possible to reduce useless energization and cause a freezing accident. It is an object of the present invention to provide a power saving type anti-freezing device which can be prevented.
[0009]
[Means for Solving the Problems]
A first means of the power saving type anti-freezing device of the present invention for achieving the above object is a freezing prevention device including a heating unit, a pipe temperature detecting unit, and an energization control unit. Is arranged so as to heat, the energization control unit starts energization of the heating unit when the detected temperature of the pipe temperature detection unit is a temperature equal to or lower than the energization start temperature, and the detected temperature is equal to or higher than the energization stop temperature. When the power supply to the heat generating unit is stopped and the elapsed time from the stop of the power supply to the start of the next power supply is equal to or less than a predetermined time, at least one of the power supply start temperature and the power supply stop temperature is set higher. .
[0010]
If the cooling is more severe than expected at the time of design, the temperature of the pipe rises due to energization, and the rate of decrease in the temperature of the pipe after stopping the energization becomes faster than expected. When such a situation is observed, freezing can be prevented by increasing at least one of the power supply start temperature and the power supply stop temperature. Accordingly, it is possible to set at least one of the predetermined energization start temperature and the energization stop temperature as low as possible, so that power can be saved.
[0011]
A second means of the power-saving type anti-freezing device of the present invention for achieving the above object is a freezing prevention device including a heating unit, a pipe temperature detection unit, an outside air temperature detection unit, and an energization control unit. The power supply control unit is arranged to heat the pipe when the power is supplied, and the power supply control unit starts supplying power to the heating unit when the detected temperature of the pipe temperature detection unit is equal to or lower than the power supply start temperature. When the above is the case, the energization of the heat generating unit is stopped, and at least one of the energization start temperature and the energization stop temperature is increased as the detected temperature of the outside air temperature detection unit falls below a predetermined temperature. Things.
[0012]
In order to achieve the above object, a third means of the power saving type antifreezing device of the present invention is characterized in that the power supply control unit is configured to supply power when a temperature detected by an outside air temperature detection unit is kept below a predetermined temperature for a predetermined time. The control unit increases at least one of the energization start temperature and the energization stop temperature.
[0013]
A fourth means of the power saving type freezing prevention device of the present invention for achieving the above object is to detect an outside air temperature when detecting that a detected temperature of the pipe temperature detecting section is equal to or lower than a preset energization start temperature. The power supply to the heating section is started regardless of the detected temperature of the section. The fourth means is for a case where the mounting position of the outside air temperature detecting unit is mounted in a place where the temperature is biased toward a higher temperature such as a place where the ambient air is heated near the boiler or where the surrounding air is heated. is there.
[0014]
The means for setting the set temperature higher may be changed once for the entire control temperature range, may be changed multiple times, and may be changed continuously by one change. Good. There is no particular limitation on the set temperature change width, and when the temperature is changed stepwise a plurality of times, the change width can be changed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to an embodiment with reference to the accompanying drawings.
[0016]
A power-saving type antifreezing device according to a first embodiment of the present invention will be described with reference to FIGS. First, a state in which a heating element (heating section) 2 and a pipe temperature sensor (pipe temperature detecting section) 3 are attached to the water distribution pipe 1 will be described with reference to FIG. In FIG. 1, a flat string-shaped heating element 2 is wound around a water pipe 1 (a water pipe in FIG. 1) at a portion which rises from a ground 4 and penetrates an outer wall 5 to be drawn into an indoor 5a.
[0017]
The pipe temperature sensor 3 is composed of a thermistor (not shown) or the like. The pipe temperature sensor 3 is attached to the water distribution pipe 1 at a predetermined height from the ground 4, and its outside is covered with a heat insulating material 6. Note that reference numeral 1a shown in FIG. 1 is a curran, 7 is a lead wire for energizing the heating element 2, and 8 is a lead wire for supplying a temperature detection signal of the pipe temperature sensor 3 to the energization control unit 9.
[0018]
The energization control unit 9 shown in FIG. 1 is based on the assumption that a plurality of sets of the heating elements 2 and the pipe temperature sensors 3 are controlled at a time, and the following description is based on the heating elements 2 attached to one water pipe. A case will be described in which the combination of the pipe and the pipe temperature sensor 3 is controlled by the power supply controller 9.
[0019]
As shown in FIG. 2 (a), the flat-string-shaped heating element 2 is made by winding a heating wire 2b around a core wire 2a made of a flexible insulating resin at a predetermined interval to form a flexible insulating material. The heating wire on the free end side is short-circuited, a through hole 2e is opened in the insulating coating 2d of the short-circuit portion, and a waterproof plug 7a is attached to the end of the other heating wire 2b. The lead wire 7 is connected. The through hole 2e is used for fixing the heating element 2 to the water distribution pipe 1 by fixing a tip portion by tying the hole 2e to a pipe through a string or the like.
[0020]
The pipe temperature sensor 3 can be composed of a thermistor (not shown) or the like, and is connected to a lead wire 8 having a waterproof plug 8a attached to an end, similarly to the heating element 2. The heating element 2 and the pipe temperature sensor 3 are connected to a power supply control unit 9 disposed outdoors, for example, through a waterproof connector 7c. Then, as shown in FIG. 1, it was attached to the water distribution pipe 1 at a predetermined height from the ground 4 and not affected by the heating element 2, and its outside was covered with a heat insulating material 6 to eliminate the influence of the outside air temperature. .
[0021]
Next, the energization control unit 9 of the first embodiment will be described with reference to FIG. A power saving type anti-freezing device 10 according to the first embodiment shown in FIG. 3 includes a microcomputer (hereinafter, microcomputer) 9b that controls a power control element 9a including a relay, a thyristor, and the like that controls power supply to the heating element 2, and a power supply display. It has a unit 9c and a DC power supply circuit 9d. Reference numeral 9e shown in FIG. 3 is a plug connected to a 100V commercial power supply (not shown).
[0022]
The microcomputer 9b controls on / off of the power control element 9a based on the detected temperature signal output from the pipe temperature sensor 3. The energization display unit 9c can be configured by a power supply, an LED (not shown) for displaying the energization state of the heating element 2, and the like.
[0023]
Next, an energization control procedure according to the first embodiment will be described with reference to a flowchart shown in FIG. In FIG. 4, when the power is supplied to the freeze prevention device 10 (FIG. 3) and the program of the microcomputer 9b is started, it is first determined in step 1 whether or not the pipe temperature is 2 ° C. or less, and a negative result is obtained. Then, step 1 is executed again, and if a positive result is obtained, in step 2, the microcomputer 9b outputs a switch-on signal for turning on the power control element 9a and energizing the heating element 2, and then step 3 is executed.
[0024]
In step 3, it is determined whether or not the pipe temperature is 4 ° C. or higher. If a negative result is obtained, step 2 is executed again. If a positive result is obtained, the energization of the heating element 2 is turned off in step 4. A switch-off signal is output at step 5 to determine whether or not the pipe temperature is 2 ° C. or less. If a negative result is obtained, at step 6 the elapsed time after the power supply to the heating element 2 is turned off is 20 minutes. It is determined whether or not it has elapsed, and if a negative result is obtained, step 4 is executed again. If a positive result is obtained, the process returns to step 1 and the above operations are repeated.
[0025]
On the other hand, if a positive result is obtained in step 5, the process proceeds to routine S, and in step S1, it is determined whether the pipe temperature is 4 ° C. or less. That is, in this procedure, the cooling is considered to have become severer when the power supply start temperature is reached before the predetermined power supply off time (the above-mentioned 20 minutes) has elapsed.
[0026]
If a negative result is obtained in step S1, step S1 is executed again. If a positive result is obtained, a switch-on signal is output in step S2. In step S3, it is determined whether or not the pipe temperature is 6 ° C. or more. If a negative result is obtained, step S2 is executed again. If a positive result is obtained, a switch-off signal is output in step S4, and step S5 is executed.
[0027]
In step S5, it is determined whether or not the pipe temperature is equal to or lower than 4 ° C. If a negative result is obtained, step S6 is executed, and if a positive result is obtained, step S7 is executed.
[0028]
In step S6, it is determined whether 15 minutes have elapsed after the output of the switch-off signal. If a negative result is obtained, step S4 is executed again. If a positive result is obtained, the process returns to the first routine and returns to step S1. Is executed.
[0029]
In step S7, it is determined whether 10 minutes have elapsed after the output of the switch-off signal. If a positive result is obtained, step S2 is executed. If a negative result is obtained, it is determined that the cooling is severe. Then, the process proceeds to a routine T, and a step T1 is executed.
[0030]
That is, in Steps S3 and S5, when the preset energization start temperature 2 ° C. and energization stop temperature 4 ° C. are each increased by 2 ° C., if the temperature decreases slowly after the energization is stopped, the temperature is returned to the original set temperature and the energization is performed. When the control is executed and the temperature decreases relatively quickly (between 10 minutes and 15 minutes), the energization control is executed as it is (ie, while the set temperature is raised by 2 ° C.), and the temperature is controlled very quickly (within 10 minutes). Is decreased, it is determined that the cooling is more severe, and the energization control with the set temperature further raised is executed.
[0031]
When step T1 is executed, a switch-on signal is output. In step T2, it is determined whether or not the pipe temperature is equal to or higher than 8 ° C. If a negative result is obtained, step T1 is executed again, and a positive result is obtained. When it is obtained, a switch-off signal is output in step T3, and step T4 is executed.
[0032]
In step T4, it is determined whether or not the pipe temperature is 6 ° C. or less. If a positive result is obtained, step T1 is executed again. If a negative result is obtained, 10 minutes have elapsed after the switch-off signal is output in step T5. If a negative result is obtained, step T3 is executed again. If an affirmative result is obtained, it is determined that the cooling has slowed down, so the routine shifts to routine S and step S1 is executed.
[0033]
While the power is connected to the power-saving type antifreeze device 10, the above-described operation is performed by changing the control temperature of the pipe temperature to three stages of 2 to 4 ° C, 4 to 6 ° C, and 6 to 8 ° C according to the degree of cooling. While continuing control.
[0034]
FIG. 5 shows the relationship between the temperature control described above and the change in the outside air temperature. A case where the temperature of the outside air starts to decrease from + 2 ° C., decreases to near −7 ° C., then starts to increase, and increases to + 2 ° C., and how the pipe temperature changes by the energization control in the flowchart of FIG. 4 will be described. .
[0035]
In FIG. 5, at time t = 0, the pipe temperature becomes 4 ° C., and the time when the power supply to the heating element 2 is stopped and the pipe temperature falls to 2 ° C. becomes faster as the temperature decreases, and falls from 4 ° C. to 2 ° C. When the time becomes 20 minutes or less, the control procedure is switched to the routine S, and the power supply stop temperature is changed to 6 ° C. and the power supply start temperature is changed to 4 ° C. Thereafter, when the temperature drop further increases and the time for the pipe temperature to decrease from 6 ° C. to 4 ° C. becomes 10 minutes or less, the routine is switched to the routine T, and the energization start temperature is changed to 6 ° C. and the energization stop temperature is changed to 8 ° C. The energization control is performed.
[0036]
After that, when the temperature decreases and the time for the pipe temperature after the power supply is stopped to decrease from 8 ° C. to 6 ° C. becomes 10 minutes or more, the routine is switched to the routine S, and the set temperature is changed to the power stop temperature of 6 ° C. and the power start temperature to 4 ° C. When the temperature further decreases and the temperature drop time becomes 15 minutes or more, the routine is switched to the first routine, and the power supply is controlled by switching the pipe temperature to the initial set temperature of 4 ° C. and the power supply start temperature to 2 ° C. is there.
[0037]
Next, the power-saving type anti-freezing device 10a of the second embodiment shown in FIG. 6 is configured such that the energization control is performed by adding the detected temperature signal from the outside air temperature sensor 9f in addition to the pipe temperature sensor 3; Since the configuration is the same as that of the power saving type anti-freezing device 10 described above, the same reference numerals are given to the same members, and the description is omitted.
[0038]
When the flowchart of the second embodiment shown in FIG. 7 starts, it is determined in step U1 of routine U whether or not the outside air temperature is 0 ° C. or less. When V1 is executed and a negative result is obtained, if a determination result that the pipe temperature exceeds 2 ° C. is obtained in step U2, step U1 is executed again, and if a determination result that the pipe temperature is 2 ° C. or less is obtained, the step is performed. A switch-on signal is output at U3, and a determination of the pipe temperature is performed at step U4.
[0039]
If the determination result at step U4 indicates that the pipe temperature is lower than 4 ° C., step U3 is executed again. If the pipe temperature is 4 ° C. or higher, a switch-off signal is output at step U5, and step U1 is executed again. You. This state is shown in a routine U shown at times t _{0 to} t ₁ in FIG.
[0040]
When the routine shifts to the routine V and the step V1 is executed, it is determined again whether or not the outside air temperature is equal to or lower than 0 ° C. If a negative result is obtained, the routine returns to the routine U and the step U1 is executed. If a positive result is obtained, it is determined in step V2 whether or not the outside air temperature is -2 ° C or lower, and if the determination result is lower than -2 ° C, the process shifts to routine W and step W1 is executed. .
[0041]
In step V2, if a determination result that the outside air temperature exceeds -2 ° C is obtained, step V3 is executed. If a determination result that the pipe temperature exceeds 2 ° C is obtained, step V1 is executed again, and the pipe temperature becomes 2 ° C. If the following determination result is obtained, a switch-on signal is output in step V4, and step V5 is executed.
[0042]
If it is determined in step V5 that the pipe temperature is lower than 6 ° C., step V4 is executed again. If it is determined that the pipe temperature is 6 ° C. or higher, a switch-off signal is output in step V6 and the process returns to step V1. Above state is in the state illustrated in routine V time _t 1 ~t ₂ in FIG.
[0043]
In step V2, it is determined that the outside air temperature is equal to or lower than -2 ° C, the process proceeds to routine W, and step W1 is executed to determine whether the outside air temperature is equal to or lower than -2 ° C, and a negative result is obtained. and step V1 is executed, the state of the routine V shown in time _t 1 ~t ₂ in FIG.
[0044]
If a positive result is obtained in step W1, if it is determined in step W2 that the pipe temperature exceeds 4 ° C., step W1 is executed again. If it is determined that the pipe temperature is 4 ° C. or less, the switch is switched in step W3. An ON signal is output, and if it is determined in step W4 that the pipe temperature is lower than 8 ° C., step W3 is executed again. If it is determined that the pipe temperature is higher than 8 ° C., a switch-off signal is output in step W5, Control is performed so as to return to step W1. This state temperature control results shown in the time t ₂ ~t ₃ in FIG.
[0045]
Step W1 are executed, Sutepppu V1 returns to the routine V when the outside air temperature is determined to exceed -2 ° C. is performed, the state of the routine V shown in time t ₃ ~t ₄ in FIG.
[0046]
A graph shown by a dotted line in FIG. 8 shows a state of temperature control by a conventional anti-freezing device using a power saving device. The power saver is a thermostat installed in the power supply circuit and is turned on and off at the outside air temperature regardless of the piping temperature. It turns on when the outside air temperature drops to 2 ° C. The power is turned off when the detected temperature is 12 ° C, and the power is turned on when the detected temperature is 6 ° C. Compared with the second embodiment shown in FIG. 8, it can be seen that the power saving effect of the power saving type freezing prevention device of the present invention is far superior.
[0047]
Incidentally, the procedure of steps U1, U2, steps V1, V2, V3 and steps W1, W2 of FIG. 7 is in the order of the processing of claim 4 of the present invention. In these steps, even when the outside air temperature is not properly detected due to a defective mounting position of the outside air temperature sensor or a change in the situation after the installation, the freeze prevention operation is executed.
[0048]
FIG. 9 shows a modification of the second embodiment. This modification is directed to an extremely cold region, in which power supply start and power supply stop set temperatures that are changed in accordance with the outside air temperature are set more finely to save power at low temperatures.
[0049]
That is, in FIG. 9, the energization start temperature is 2 ° C. when the outside air temperature is between 2 ° C. and −2 ° C., whereas the energization stop temperature is 4 ° C. and 0 ° C. when the outside air temperature is between 2 ° C. and 0 ° C. When the outside air temperature is between −2 ° C. and −8 ° C., the energization start temperature is 4 ° C., and when the outside air temperature is between −2 ° C. and −5 ° C., 8 ° C. When the outside air temperature is between -8C and -11C, the energization start temperature is 6C, and when the outside air temperature is -11C or less, the energization start temperature is 8C. On the other hand, the energization stop temperature is 12 ° C. when the outside air temperature is −8 ° C. or less.
[0050]
The third embodiment shown in the flowchart shown in FIG. 10 uses the power saving type anti-freezing device 10a shown in FIG. 6 and performs control different from that of the second embodiment. When the flowchart shown in FIG. 10 starts, it is determined in step X1 whether or not the outside air temperature is 0 ° C. or less for 60 minutes. If it is determined that the temperature is 60 minutes or more, the process proceeds to step Y1 of the routine Y and proceeds to step X1. If it is determined that it is less than the predetermined value, step X2 is executed.
[0051]
Steps X2 to X5 are the same processing procedures as steps U2 to U5 of the routine U in FIG. Control by the step X2~X5 indicates the control state of the routine X shown in time _t 1 ~t ₂ of Figure 11.
[0052]
When the routine proceeds to the routine Y, it is determined in a step Y1 whether or not the outside air temperature is 0 ° C. or lower. If a negative result is obtained, the routine returns to the routine X and the step X1 is executed. If a positive result is obtained, step Y2 is executed.
[0053]
In step Y2, it is determined whether or not the outside air temperature has been kept below −2 ° C. for 60 minutes. If a positive result is obtained, the process proceeds to routine Z, step Z1 is executed, and if a negative result is obtained, steps Y3 to Y3 are performed. Y6 is executed _. This step is the same processing procedure as V3 to V6 of the routine V in FIG. The process temperature control state routine Y time _t 2 ~t ₃ of Figure 11 is obtained.
[0054]
When the step Z1 is executed, it is determined whether or not the outside air temperature is lower than -2 ° C., and when a negative result is obtained, the process proceeds to the routine Y, where the step Y1 is executed, and a positive result is obtained. And step Z2 are executed. Steps Z2 to Z5 are the same processing procedures as steps W2 to W5 in FIG. Processing in step Z2~Z5 the control of the state illustrated routines Z time _t 3 ~t ₄ of FIG. 11 is performed.
[0055]
The power saving type anti-freezing device 10b shown in FIG. 12 is provided with one energization control unit 9 for one heating element 2, and provided with a socket 9g in the energization control unit 9 to separate it from another. The heating unit (not shown) is connected, and the outside air temperature detection unit (not shown) is housed in the casing of the power supply control unit 9. In this way, it is possible to replace the heat generating portion which is most severely damaged in use. As for the other members, the same members as those described in FIGS. 1 and 3 are denoted by the same reference numerals, and description thereof will be omitted.
[0056]
The power saving type anti-freezing device 10c shown in FIG. 13 has the pipe temperature sensor 3 and the heating element 2 integrated. In the portion where the pipe temperature sensor 3 is disposed, the heating wire is changed to an electric wire (both not shown) so that the temperature of the heating section is not detected by the pipe temperature sensor 3. Reference numeral 12 shown in FIG. 13 denotes a wire portion that bundles lead wires of the heating element 2, the pipe temperature sensor 3, and the like, and 13 denotes a power supply connection lead wire. Further, members similar to those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted.
[0057]
【The invention's effect】
As described above, the power-saving type anti-freezing device of the present invention detects the pipe temperature, captures the tendency of the pipe temperature to decrease when power supply is stopped, and controls the temperature in accordance with the change in the outside air temperature or further controls the outside air temperature. By detecting the temperature and changing the set temperature according to the change in the outside air temperature, more precise temperature control can be performed to prevent freezing and prevent unnecessary power consumption as much as possible. Was completed.
[0058]
In addition, when the outside air temperature detecting unit cannot appropriately detect the outside air temperature, the anti-freezing operation is executed prior to the power saving operation, and the accident of freezing of the water distribution pipe can be avoided.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a state in which a heating element for preventing freezing used in the present invention is applied to a water pipe.
FIG. 2 is a schematic explanatory view of a structure of a heat generating unit used in FIG.
FIG. 3 is a block circuit diagram illustrating an outline of a circuit configuration of the power saving type anti-freezing device according to the first embodiment of the present invention.
FIG. 4 is a flowchart showing a power supply control procedure of the power saving type anti-freezing device shown in FIG. 3;
FIG. 5 is a graph showing how the control temperature changes according to a power supply control procedure of the power saving type anti-freezing device shown in FIG. 3;
FIG. 6 is a block circuit diagram illustrating a circuit outline of a power saving type anti-freezing device used in a second embodiment and a third embodiment of the present invention.
FIG. 7 is a flowchart illustrating a power supply control procedure according to a second embodiment using the block circuit diagram illustrated in FIG. 6;
FIG. 8 is a graph showing a temperature control according to the power supply control procedure shown in FIG. 7 and a temperature control state of a freeze prevention device using a conventional power saving device.
FIG. 9 is a modified example of the second embodiment, and is a graph showing an example in which power saving in an extremely cold region is set more finely.
FIG. 10 is a flowchart showing a power distribution control procedure of a third embodiment using the block circuit diagram shown in FIG. 6;
11 is a graph showing an example of a change in pipe temperature according to the energization control procedure shown in FIG.
FIG. 12 is an external perspective view showing an example in which a power-saving type anti-freezing device used in the present invention is integrated _.
FIG. 13 is an external perspective view of an integrated power-saving type anti-freezing device different from FIG.
[Explanation of symbols]
2 Heating element (heating section)
3 Pipe temperature sensor (Pipe temperature detector)
9 Power supply control section 9a Power control element 9b Microcomputer 9c Power supply display section 9f Outside air temperature sensor (outside air temperature detection section)

Claims (4)

In a freeze prevention device including a heating unit, a pipe temperature detection unit, and an energization control unit, the heating unit is arranged to heat a pipe when energized, and the energization control unit detects a temperature detected by the pipe temperature detection unit. If the temperature is lower than the energization start temperature, energization of the heat generation part is started.If the detected temperature is higher than the energization stop temperature, energization of the heat generation part is stopped, and the elapsed time from the stop of energization to the start of the next energization is predetermined. A power saving type freezing prevention device characterized by raising at least one set temperature of an energization start temperature and an energization stop temperature when the time is equal to or less than a predetermined time. In a freezing prevention device including a heating unit, a pipe temperature detection unit, an outside air temperature detection unit, and an energization control unit, the heating unit is arranged to heat the pipe when energized, and the energization control unit detects the pipe temperature. When the detected temperature of the unit is equal to or lower than the energization start temperature, the energization of the heat generating unit is started. A power saving type freezing prevention device characterized by increasing at least one of the energization start temperature and the energization stop temperature as the temperature falls below a predetermined temperature. The energization control unit increases a set temperature of at least one of the energization start temperature and the energization stop temperature when a temperature detected by the outside air temperature detection unit is equal to or lower than a predetermined temperature for a predetermined time. The power-saving type anti-freezing device according to claim 2. When detecting that the detection temperature of the pipe temperature detection unit is equal to or lower than the preset power supply start temperature, the power supply to the heating unit is started regardless of the detection temperature of the outside air temperature detection unit. The power saving type freezing prevention device according to claim 2 or 3, wherein:

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