JP4285607B2 - Freezing prevention device - Google Patents

Description

  The present invention relates to an anti-freezing device, and more specifically, in a water / hot water supply facility in which a normal water supply pipe and a hot water supply pipe coexist, a pipe temperature sensor is attached to the hot water supply pipe, and antifreezing control of all pipes is possible even during hot water supply. The present invention relates to a freezing prevention device.

  Conventionally, in order to prevent water pipes and the like from freezing in cold districts, it is well known that, for example, an anti-freezing band made of an electric heater insulated with a flat string-like flexible resin is wound around a water distribution pipe. It is. The energization control of the electric heater is usually equipped with a thermal reed switch and a thermostat, and the power is turned on when the temperature falls to a certain temperature and turned off when the temperature rises to a certain temperature. .

  However, since this method cannot be expected to detect temperature with high accuracy, it is necessary to set the temperature at which the switch is turned on and off to a high value, for example, 6 ° C or 12 ° C. There is a problem that becomes excessive.

Therefore, the present inventor uses a thermistor or the like that is excellent in following the temperature change for the pipe temperature sensor, starts energizing the electric heater when the temperature falls below a certain temperature, and stops energizing when the temperature rises above a certain temperature As the temperature detected by the outside air temperature sensor falls below a predetermined temperature, at least one of the energization start temperature and energization stop temperature is increased to save power efficiently. The prevention device was invented, and a patent application (hereinafter referred to as a prior application invention) was filed as the following patent document.
JP 2004-044297

  By the way, in cold districts, there are many places where water pipes and hot water supply pipes need to be prevented from freezing even in ordinary households and small factories, and all pipes are almost all free of freeze operation. Is generally required. On the other hand, temperature control devices that use high-performance pipe temperature sensors such as thermistors are more expensive than conventional temperature controls such as thermostats, so installing pipe temperature sensors on all pipes increases the cost. There is.

  Therefore, conventionally, it is possible to connect multiple anti-freezing zones in parallel to one control device, attach one pipe temperature sensor to any pipe, and control other pipes together with one temperature signal. Has been done. In such a case, since the region where the antifreezing device is used is naturally a cold region, a hot water supply pipe is often included in the water supply pipe controlled at the same time. In this case, if the piping temperature sensor is attached to the hot water supply pipe for some reason, the control device does not perform the freeze prevention operation even if the outside air temperature is in a freezing danger state during hot water supply, and the hot water supply is not started from the water supply pipe. There is a risk of freezing accidents in hot water pipes.

  As described above, the installation error of the piping temperature sensor is a matter of course, especially when the construction is well managed in the new construction. There are a lot of parts, equipment that is usually not paying attention, and that the worker who lays the anti-freeze belt may not be a person who has received training for handling the anti-freeze device, the time when the freeze problem occurs However, there is a problem that construction mistakes are difficult to be discovered until the freezing noise occurs.

  The present invention has been made paying attention to the above-mentioned problems. When a plurality of anti-freezing bands are attached to one energization controller and energization control is performed simultaneously by one pipe temperature sensor, it happens to happen. It is an object of the present invention to provide an anti-freezing device in which a pipe temperature sensor is attached to a hot water supply pipe and the anti-freezing control can be performed without any trouble even when a freezing condition of the water distribution pipe occurs during the hot water supply.

  In order to achieve the above object, the antifreezing device of the present invention includes a plurality of antifreezing zones comprising an electric heater for preventing freezing of water in a pipe, a pipe temperature sensor attached to one of the pipes, and an outside air temperature sensor. The energization control unit has a normal mode and a hot water supply mode. In the normal mode, when the outside air temperature is equal to or lower than a predetermined temperature, the detection temperature of the pipe temperature sensor is set in advance. When the temperature is equal to or lower than a predetermined energization start temperature, energization control is performed on the plurality of electric heaters all at once, and then the energization is stopped at once when a predetermined energization stop temperature is reached. The detected temperature of the pipe temperature sensor is equal to or lower than a predetermined temperature exceeding the energization stop temperature, or the change rate of the detected temperature is equal to or lower than a predetermined value. The control is performed when at least one of these is detected, and the predetermined energization time and the energization stop time are alternately repeated until the temperature detected by the pipe temperature sensor reaches the energization stop temperature or lower. Control is performed.

  There is no particular limitation on the outside air temperature condition for the normal mode state, and it can be set to a temperature at which freezing may occur if the temperature rapidly decreases from the present state, for example, a temperature around 2 ° C. In this way, it is possible to obtain a power saving effect while preventing freezing.

  There is no particular limitation on the determination temperature for shifting from the normal mode to the hot water supply mode, and the determination temperature can be determined according to actual conditions. For example, since the conventional energization stop temperature is generally about 12 to 16 ° C., in such a case, a temperature with an allowance for the energization stop temperature in the antifreezing zone, for example, the hot water supply pipe temperature is 20 ° C. or more. When it becomes, it can determine with hot water supply.

  Moreover, there is no limitation in particular also in the determination temperature change rate which transfers to normal hot water supply mode, Although it depends on hot water supply temperature, it can be set to 15 degree-C / min or more, for example. If temperature change is used as an index for mode switching, there is a feature that mode switching determination is possible at an early stage of temperature rise.

  Note that a commercially available anti-freezing zone is generally provided with a dedicated thermostat. Therefore, in this case, even if the pipe temperature sensor attached to the hot water supply pipe detects the hot water supply state and the energization control unit starts energization, the temperature of the hot water pipe attached with the pipe temperature sensor rises due to the hot water supply. In addition, the thermostat is turned off, and no power is consumed even if the hot water pipe is energized. However, there is a case where the thermostat is used for detecting the outside air temperature without attaching the thermostat to the pipe. In such a case, current also flows through the electric heater of the hot water supply pipe during hot water supply.

  Therefore, if the switching time between the energization time and the energization stop time is made constant in the hot water supply mode, there is a possibility that the setting conditions may not match the energization conditions actually required by the water supply pipe. Therefore, in the hot water supply mode, at least one of the energization time and the energization stop time is provided with a preset minimum time and maximum time, and after an elapsed time from the energization start or energization stop operation, the minimum time has elapsed, The elapsed time after the start of energization reaches the maximum time, or the temperature rise after the start of energization is set to a predetermined temperature increase range (which may be determined according to actuality, for example, 1 ° C.). Or the elapsed time after the energization stop reaches the maximum elapsed time, or the temperature decrease width after the energization stop is determined in advance according to a predetermined temperature decrease width (for example, 2 ° C. ), The water supply pipe and the hot water supply are switched according to the environment against freezing from the relationship between the temperature range and the time by switching the energization stop or energization start. It can be appropriately controlled freezing of the hot water supply pipe have become.

  By the way, the reason for setting the minimum time for the energization stop time is that, during hot water supply, the higher the hot water pipe temperature, the faster the heat dissipation rate from the hot water pipe, and the shorter the time for the temperature drop to reach the temperature reduction range, This is to prevent the heat from becoming insufficient.

  The reason for setting the maximum time for the energization stop time is that the pipe temperature does not decrease due to continuous hot water supply or the pipe temperature rises due to re-hot water supply. This is to prevent the length from becoming extremely long.

  The reason for providing the minimum energization time in the energization time is that the case where the temperature of the hot water supply pipe rises due to re-heating is considered, and the actual temperature change of the hot water supply pipe is too fast due to the energization, and reaches the energization stop temperature increase range. This is to prevent the time from being shortened and the energization time to the hot water supply pipe and the hot water supply pipe not in the hot water supply state from being shortened.

  The reason why the maximum energization time is set for the energization time is that when a thermostat is attached to a hot water supply pipe to which a temperature sensor is attached, the energization to the electric heater is off during hot water supply. This is because it is determined that an increase cannot be obtained and energization is continued, and the piping temperature is prevented from becoming abnormally high.

The minimum time and the maximum time can be determined in a plurality of stages according to the outside air temperature. An example is shown below. However, the present invention is not limited to this, and arbitrary conditions can be selected as long as the essence of the invention is not changed.
a) When energized:
Outside temperature: -3 ° C to 2 ° C; energize for a maximum of 10 minutes and a minimum of 5 minutes
-9 ° C to -4 ° C; energize for a maximum of 20 minutes and a minimum of 10 minutes
-10 ° C or lower; Energize for a maximum of 30 minutes and a minimum of 20 minutes b) When energization is stopped:
Outside temperature: -3 ° C to 2 ° C; stop energization for a maximum of 60 minutes and a minimum of 20 minutes
−4 ° C. or less; Energization stop for a maximum of 30 minutes and a minimum of 10 minutes In order to make the energization control conditions more appropriate, the energization start temperature and the energization are increased as the detected temperature of the outside temperature sensor falls below a predetermined temperature. It is possible to increase the set temperature of at least one of the stop temperatures. The temperature range to be increased can be appropriately determined according to the actual situation.

  When a temperature equal to or lower than a predetermined temperature detected by the outside air temperature sensor is continued for a predetermined time, at least one of the energization start temperature and the energization stop temperature can be increased.

  When it is detected that the detection temperature of the pipe temperature sensor is equal to or lower than the predetermined energization start temperature, the energization can be started regardless of the detection temperature of the outside air temperature detection sensor.

  The anti-freezing device of the present invention has a piping temperature sensor attached to the hot water supply pipe when the hot water supply / water supply equipment in which the hot water supply pipe and the hot water supply pipe are mixed is used to prevent freezing by one pipe temperature sensor. Therefore, even when the detected temperature is higher than the piping temperature of the hot water supply pipe and the hot water supply pipe that is not hot water supplied, it is possible to achieve the effect that the antifreezing control of the entire hot water supply / water supply equipment can be performed. Therefore, it is possible to prevent a freezing accident even when the pipe to which the pipe temperature sensor is attached is mistaken and not noticed.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an antifreezing apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  The antifreezing device 1 according to the first embodiment shown in FIGS. 1 to 4 has an anti-air temperature sensor (not shown) connected to the antifreezing zones 3a and 3b equipped with the thermostat 2 by a branch cord 8, as shown in FIG. It is connected in parallel to the built-in energization control unit 4, and the energization control of the electric heaters (not shown) provided in the anti-freezing zones 3 a and 3 b is performed simultaneously by the temperature signal given from the pipe temperature sensor 5. Is. And this 1st Embodiment shows the electricity supply control in case the piping temperature sensor 5 is attached to the hot water supply pipe 6a.

  In addition, the hot water supply pipe 6a and the water supply pipe 6b of the part shown in FIG. 1 is a heat insulating material, 10a is a female side of the connector, and 10b is a male side of the connector. Although the branch cord 8 shown in FIG. 1 shows two, the one with a large number can be used as long as the allowable current capacity of the energization control unit 4 allows. Moreover, it can implement by other means, such as attaching a some connector directly to the electricity supply control part 4 instead of attaching to a branch cord.

  When the energization control method of the freeze prevention device 1 shown in FIG. 1 is a control method based on the assumption that the pipe temperature sensor 5 is attached to the water supply pipe, the pipe temperature sensor 5 to be attached to the water supply pipe 6b is FIG. 2 explains what kind of problem occurs when an operator mistakenly attaches the hot water pipe 6a.

In FIG. 2, after reaching the piping temperature (for example, 2 ° C.) at which energization is started to prevent freezing and energization control is started, the outside air temperature is below the freezing point, and then hot water supply is started at time t _1. When the pipe temperature rises and the energization stop temperature T ₂ is reached (time t ₂ ), the energization is stopped, but the pipe temperature rises until the hot water supply is stopped or the hot water temperature is reached. Thereafter, the hot water supply is repeated intermittently (four times in FIG. 2) until the time t ₄ is reached, but during that time, the temperature of the water supply pipe 6b drops because the power supply is stopped at the time t ₂ and reaches 0 ° C. If this state continues for a long time (time t ₃ ), it freezes and water supply becomes impossible.

When the series of hot water supply ends (time t ₄ ), the temperature of the hot water supply pipe 6a starts to decrease, and when the energization start temperature T ₁ is reached (time t ₅ ), energization is started again. Thus, hot water supply pipe 6a, the temperature of the water supply pipe 6b rises each to a temperature of the hot water supply pipe 6a reaches the energization stop temperature T _2, then deenergized, the temperature of the water supply pipe 6b is gradually increased for each repeat start of energization Unless the hot water is supplied again, the temperature of the hot water supply pipe 6a is finally reached, and thereafter the same temperature change is repeated until the outside air temperature reaches the set temperature.

  As described above, it is understood that the work of attaching the conventional anti-freezing device that does not consider the case where the pipe temperature sensor 5 is mistakenly attached to the hot water supply pipe requires a skilled worker who is well equipped with the technology. Let's be done. However, in practice, it is difficult to always satisfy such a condition, and it is necessary to be able to perform an antifreezing operation even if a pipe temperature sensor is attached to any pipe.

  According to FIG. 3, when energizing in the hot water supply mode, the setting of the temperature rise range that is a condition for stopping energization within the maximum energization time, and the temperature decrease range that is the condition for starting energization within the maximum energization stop time when energization is stopped. The setting will be described.

  3 shows in detail the state of temperature change in the hot water supply mode when a thermostat (not shown in FIG. 3) is not attached to the hot water supply pipe as shown in FIG. 1, and is similar to FIG. Are given the same writing or explanation and the explanation is omitted.

  FIG. 3 shows that hot water supply is started, the energization control device detects a rise in temperature, switches the energization control mode to the hot water supply mode, and then is closed and the temperature of the hot water supply pipe starts to decrease, and the energization is performed while the temperature decreases (see FIG. 3). The temperature change until the normal mode is entered while alternately repeating the energization stop (the portion indicated by the solid line in FIG. 3) and the energization stop (the portion indicated by the dotted line). That is, while the hot water supply pipe temperature during energization stops constantly, the change in hot water supply pipe temperature during energization decreases while the hot water supply pipe temperature falls even if the power is turned on because the heat dissipation is large while the temperature is sufficiently high. The amount of heat released decreases and increases.

If the hot water supply pipe temperature rises due to energization after the hot water supply is stopped, the temperature TA decreased during the energization stop. If the temperature TB raised during energization is larger, the hot water supply pipe temperature will gradually increase. Therefore, in the first embodiment, the temperature increase width TB that is a determination criterion for stopping energization during energization is set to be smaller than the temperature decrease width TA that is a determination criterion for starting energization while energization is stopped.

  The flowcharts shown in FIGS. 4 and 5 are explanatory diagrams of the operation of the energization control unit of the freeze prevention device according to the first embodiment of the present invention. That is, the flowchart shows a case where freezing of the water supply pipe 6b can be prevented even if the pipe temperature sensor 5 is attached to the hot water supply pipe 6a. In this case, since the external appearance of the anti-freezing device is the same as that of FIG. 1, the external view is not shown again, the same reference numerals are used for the same members, and different portions of the functions will be clarified by explanation.

  In FIG. 4, when the energization control unit 4 is turned on, the program starts. First, in step 1, the outside air temperature is detected, and the detected temperature of an outside air temperature sensor (not shown) built in the energization control unit is the antifreezing temperature. It is determined whether or not (for example, 2 ° C.) or less. If a negative result is obtained, step 1 is executed again. If a positive result is obtained, the process proceeds to step 2 to determine whether hot water is supplied. Determined.

  That is, in step 2, it is determined whether or not the hot water pipe temperature has exceeded 20 ° C. and whether the rate of temperature increase is 15 ° C./min or more. If a positive result is obtained, the process proceeds to step S1 of the program shown in FIG.

  First, a case where a negative result is obtained will be described. If a negative result is obtained, it is determined in step 3 whether or not the detected temperature of the pipe temperature sensor 5 (hereinafter simply referred to as pipe temperature) is the energization start temperature (for example, 6 ° C. or less), and a negative result is obtained. Step 2 is executed again, and if a positive result is obtained, an electric heater (not shown) is energized in Step 4, and in Step 5, the temperature detected by the pipe temperature sensor 5 is the energization stop temperature (for example, 12 ° C. or higher). If a negative result is obtained, step 5 is executed again. If a positive result is obtained, the energization is stopped in step 6 and then step 1 is executed again.

When a positive result is obtained in step 2, the hot water supply mode program is executed. In step S1 of the flowchart of FIG. 5, the detected temperature T _ON of the pipe temperature sensor 5 is stored, and in step S2, the outside air temperature is detected. The maximum energization time (for example, 10 minutes) and the minimum energization time (for example, 5 minutes) preset by the outside air temperature stored in advance in the storage device (not shown) of the energization control unit 4 are read, and then frozen in step S3. The electric heaters of the prevention bands 3a and 3b are energized. In step S4, it is determined whether or not the minimum time has elapsed from the start of energization. If a negative result is obtained, step S4 is executed again to obtain a positive result. In step S5, the pipe temperature (detected temperature of the pipe temperature sensor 5) T _OFF is measured, and in step S6 It is determined whether or not the temperature rise from the stored T _ON is equal to or greater than a predetermined temperature range (for example, 1 ° C.). If a negative result is obtained, whether or not the maximum energization time has been reached in step S7. If a negative result is obtained, step S5 is executed again. If a positive result is obtained, the process proceeds to step S8. If a positive result is obtained in step S6, the process directly proceeds to step S8.

When step S8 is executed, the energization to the electric heater is stopped, and the pipe temperature T _OFF finally measured in step S9 is stored. In step S10, the outside air temperature is detected and stored in the storage device. When the maximum energization stop time (for example, 60 minutes) and the minimum energization stop time (for example, 20 minutes) to the electric heater are read out, it is determined whether or not the minimum energization stop time has elapsed in step S11, and a negative result is obtained. Step S11 is executed again, and when a positive result is obtained, the process proceeds to step S12.

In step S12, the pipe temperature T _ON is measured, and it is determined whether or not the T _ON measured in step S13 is equal to or lower than the energization stop temperature in the normal mode. If a positive result is obtained, the normal mode shown in FIG. When the process proceeds to step 1 and a negative result is obtained, the process proceeds to step S14.

When step S14 is executed, it is determined whether or not the difference between the pipe temperature T _OFF stored in step S9 and the pipe temperature T _ON measured in step S12, that is, a temperature decrease width (for example, 2 ° C.) or more. If a positive result is obtained, the process proceeds to step S1. If a negative result is obtained, it is determined in step S15 whether or not the maximum energization stop time has elapsed. If a negative result is obtained, step S12 is performed. When executed, if a positive result is obtained, step S1 is executed.

  In the second embodiment shown in FIG. 6, the normal mode is implemented by a power-saving program according to the invention of the prior patent application, and the hot water supply mode program is the same as that of the first embodiment, so that the description thereof is omitted. When the program shown in FIG. 6 is started and the detected outside air temperature has reached the start temperature (for example, 2 ° C.) of the freeze prevention control or less, it is determined whether or not the pipe temperature is in the hot water supply state. If it is determined that the outside air temperature has reached the freezing point in step U1, the control operation in the energization mode shifts to the hot water supply mode. When the process goes to V1 and the freezing point is not reached, Step U2 is executed.

  In step U2, energization is performed when the pipe temperature is 2 ° C. or lower, monitoring is continued until the pipe temperature exceeds 4 ° C., and energization is stopped when the temperature exceeds 4 ° C., and the process proceeds to step T1.

  When the process proceeds from step U1 to step V1, it is determined whether the outside air temperature> 0 ° C., 0 ° C. ≧ outside air temperature> −2 ° C., −2 ° C. ≧ outside air temperature. In the meantime, it is detected whether or not hot water is being supplied (step V2). If it exceeds 0 ° C., the process returns to step T1. If −2 ° C. ≧ outside air temperature, the process proceeds to step W1, and if it is an intermediate level, step V4 is executed.

  When the outside air temperature is at the intermediate level (0 ° C. or lower to −2 ° C.), energization is started when the piping temperature is equal to or lower than the energization start temperature (for example, 2 ° C.) at the intermediate level (step V5). It is monitored that the temperature becomes equal to or higher than the energization stop temperature (for example, 6 ° C.) at the intermediate level.

  When the process proceeds to the step W1, the determination as to whether or not the outside air temperature is −2 ° C. or lower and the determination as to whether or not the hot water supply state is present (step W2) are executed again. When the temperature is below the energization stop temperature (for example, 4 ° C) at the low temperature level, energization is started, and it is monitored that the pipe temperature becomes the energization stop temperature (for example, 8 ° C). By performing step W1, fine freeze prevention can be performed.

  FIG. 7 shows a modification of the second embodiment, in which an energization control program in which the energization start temperature and the energization stop temperature are further finely divided according to the outside air temperature is configured and executed, and finer power saving is performed. is there. The data collection method for graphing is a method in which the measured outside air, each temperature of the hot water supply pipe 6a and the water supply pipe 6b are time-sequentially taken into a personal computer (not shown) and graphed by the graph creation software after data collection. is there. In the figure, the hot water supply detection signal indicates that the temperature of the hot water supply pipe 6a is stopped when the temperature of the hot water supply pipe reaches 20 ° C. or higher or a temperature rise of 15 ° C./min or higher is detected. Until the temperature falls below the temperature, it is determined and recorded that the hot water is in a hot water supply state, and is printed out as a hot water supply detection signal at the time of graphing.

1 is a schematic explanatory diagram of an overall configuration of a freeze prevention device according to an embodiment of the present invention. FIG. 2 is a graph for explaining problems in the case of using a conventional control method in the freeze prevention device shown in FIG. 1. FIG. 2 is a graph showing in detail the state of temperature change in the hot water supply mode in the freeze prevention device of FIG. 1. It is a flowchart figure of the normal mode in 1st Embodiment. It is a flowchart figure of the hot water supply mode in 1st Embodiment. It is a flowchart figure of the normal mode by 2nd Embodiment. It is a graph figure of the actual measurement data by the modification of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Freezing prevention apparatus, 3a ... Freezing prevention zone, 3b ... Freezing prevention zone, 4 ... Current supply control part, 5 ... Pipe temperature sensor, 6a ... Hot water supply pipe, 6b ... Water supply pipe

Claims (6)

It consists of a plurality of anti-freezing zones consisting of electric heaters that prevent freezing of water in the pipe, a pipe temperature sensor attached to any of the pipes, an outside air temperature sensor, and an energization control unit. There is a mode and a hot water supply mode. In the normal mode, when the outside air temperature is equal to or lower than a predetermined temperature, when the detected temperature of the pipe temperature sensor is equal to or lower than a predetermined energization start temperature, the plurality of electric heaters are simultaneously The energization control is performed, and then the energization is stopped when the predetermined energization stop temperature is reached.In the hot water supply mode, the outside air temperature is equal to or lower than the predetermined temperature, and the detected temperature of the pipe temperature sensor is In the control when at least one of the temperature exceeding the predetermined temperature exceeding the energization stop temperature or the change rate of the detected temperature is equal to or higher than a predetermined value is detected. I, the pipe until the temperature detected by the temperature sensor reaches below the energization stop temperature, antifreeze apparatus that performs control to repeat the energizing time a predetermined energization stop time alternately. In the hot water supply mode, at least one of the energization time and the energization stop time is provided with a preset minimum time and maximum time, and after the minimum time has elapsed after the energization start or energization stop operation has elapsed, the energization start Whether the later elapsed time reaches the maximum time, whether the detected temperature reaches a predetermined temperature rise after the start of energization, or whether the elapsed time after the energization stops reaches the maximum elapsed time The anti-freezing device according to claim 1, wherein when the temperature decrease width after the energization stop reaches a predetermined temperature decrease width, the energization stop or the energization start is switched. The antifreezing device according to claim 2, wherein the minimum time and the maximum time are determined in a plurality of stages according to an outside air temperature. 4. In the normal mode, the set temperature of at least one of the energization start temperature and the energization stop temperature is increased as the detected temperature of the outside temperature sensor falls below a predetermined temperature. The antifreezing apparatus according to any one of the above. 5. The temperature set forth in claim 4, wherein at least one of the energization start temperature and the energization stop temperature is increased when a temperature equal to or lower than a predetermined temperature detected by the outside air temperature sensor continues for a predetermined time. The antifreezing device described. 6. The method according to claim 4, wherein when it is detected that the detected temperature of the pipe temperature sensor is equal to or lower than the predetermined energization start temperature, energization is started regardless of the detected temperature of the outside air temperature sensor. The antifreezing device described.

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