JP2008075900A - Propagation preventing method against ice attached to wall surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propagation preventing method against ice attached to a wall surface, capable of making upstream-side piping of a supercooling releasing device hard to be coated with ice without lowering efficiency and complicating a structure, or easily separating ice even when ice coating is found, thus the growing and expansion of ice on the upstream-side piping of the supercooling releasing device can be prevented, and a continuous operation of a system can be stabilized. <P>SOLUTION: In this propagation preventing method, an expansion preventing film 16 for inhibiting attachment of ice and preventing its growing and expansion, is formed on at least an inner face of a supercooling heat storage material introduction nozzle 12 as piping for introducing a supercooling heat storage material to the supercooling releasing device, and an operation is performed in a state that a flow velocity V of the supercooling heat storage material flowing in the supercooling heat storage material introduction nozzle 12 as the piping does not become under a predetermined lower limit value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for preventing propagation of wall-attached ice.

  FIG. 4 shows an example of an ice heat storage system that has already been developed by the present inventors. In the figure, 1 is a refrigeration unit that obtains a low-temperature refrigerant by a refrigeration cycle. Using the aqueous solution, the heat storage material cooled to the supercooled state by the supercooler 2 in which the refrigerant of the refrigeration unit 1 is circulated is released from the supercooling by the supercooling release device 3 to produce ice water below the freezing point. While supplying to the heat storage tank 4, the heat storage material at the bottom of the ice water heat storage tank 4 is returned to the supercooler 2 and circulated, and the ice water stored in the ice water heat storage tank 4 is discharged from an ice water outlet (not shown). It is configured to be taken out and used as a cold heat source.

  The supercooling release device 3 has a cylindrical main body 8 as shown in FIGS. 5 and 6, and the lower end of the main body 8 has a truncated conical portion whose diameter is reduced toward the end portion. 9, and a frustoconical portion 9 ′ is also formed at the upper end of the main body 8, and an ice water discharge port 10 is formed at the center of the end, and the lower end of the main body 8 and the frustoconical portion 9 are A supercooling heat storage material introduction nozzle 12 that is connected in the tangential direction is provided in the vicinity of the connecting portion 11, and the supercooling heat storage material introduction nozzle 12 is supercooled by the supercooler 2 (see FIG. 4). A heat storage material is guided, and at the end (bottom surface) of the truncated cone-shaped portion 9 is provided a trigger supply port 13 for supplying a trigger for releasing the supercooled state inside the truncated cone-shaped portion 9; For example, a gas supply device 15 capable of supplying air 14 is connected to the trigger supply port 13 as the trigger. .

  The supercooling heat storage material introduction nozzle 12 has a tip 12a outer peripheral surface formed in a tapered shape and protrudes inside the main body 8.

  That is, in the ice heat storage system as described above, the heat storage material is cooled to the supercooling state by the supercooler 2 through which the refrigerant of the refrigeration unit 1 is circulated, and then the supercooling release device 3 releases the supercooling. Thus, sherbet-like ice water below the freezing point is manufactured, supplied to the ice water heat storage tank 4 and stored. Here, as the supercooling release device 3, swirling as shown in FIG. 5 and FIG. When the flow type is adopted, the supercooled heat storage material supercooled by the supercooler 2 is separated from the lower end of the main body 8 of the supercooling release device 3 and the truncated cone by the supercooling heat storage material introduction nozzle 12. In the vicinity of the connecting portion 11 with the shape portion 9 is supplied from a tangential direction, and forms an upward swirling flow S1 toward the ice water discharge port 10 and at the same time forms a strong swirling flow S2 toward the frustoconical portion 9; At this time, the lower end of the truncated cone portion 9 is closed. The upward force is increased by the strong swirl flow S2 because it is not allowed to flow downward, so the withdrawal flow toward the tangential introduction portion disappears, and a stable upward flow Y is formed, The air 14 supplied from the trigger supply port 13 by the gas supply device 15 is refined by the strong swirl flow S2 in the frustoconical portion 9 and mixed with the supercooled heat storage material to release the supercooled state. Further, the finer bubbles do not form an air column, and rise along the upward flow Y while swirling together with the ice water of the heat storage material released from the supercooling, and the ice water of the heat storage material released from the supercooling. Is discharged from the ice water discharge port 10 and supplied to the ice water heat storage tank 4.

  Incidentally, in the swirling flow type supercooling release device 3 as shown in FIGS. 5 and 6, ice generation is maximized inside the truncated cone portion 9, but the truncated cone portion Since a strong swirl flow S2 is formed inside 9, the effect of stripping off the ice is strong, so that it is possible to prevent the problem that the ice adheres to the inner surface of the frustoconical portion 9 and grows and progresses. In addition, a frustoconical portion 9 'is also formed at the upper end of the main body 8, and a strong swirl flow is also formed inside the frustoconical portion 9', so that the frustoconical portion 9 ' Can prevent the problem of growth and progress due to ice adhering to the inner surface of the steel. Further, inside the main body 8, the swirl flow S <b> 1 acts so that bubbles and ice having a small specific gravity gradually gather on the axial center side of the main body 8. The release of the state is completed, and conversely, since ice formation is weakened in the vicinity of the inner surface of the main body 8, the problem of ice adhering and growing on the inner surface of the main body 8 is reduced.

  However, since the portion of the supercooling heat storage material introduction nozzle 12 connected to the supercooling release device 3 serves as a boundary between supercooling water and ice water, ice adhering to the inner surface of the main body 8 of the supercooling release device 3 is excessive. If it grows and progresses from the cooling heat storage material introduction nozzle 12 to the pipe on the upstream side of the supercooler 2 and further reaches the heat transfer pipe of the supercooler 2, there is a possibility of blocking and continuous operation being hindered.

For this reason, conventionally, by heating the outside of the pipe on the upstream side of the supercooling release device and melting the ice, the growth / progress of the supercooling release device is prevented (for example, see Patent Document 1). By injecting ice water of 0 [° C] from a small-diameter pipe provided on the inlet side so that the flow velocity in the pipe exceeds a predetermined value, the ice is separated by fluid force, and the phase change from supercooled water to ice occurs. A device for preventing the propagation to the upstream side (for example, see Patent Document 2) has been proposed.
Japanese Patent No. 2727754 Japanese Patent No. 3338657

  However, as disclosed in Patent Document 1, by heating the outside of the pipe on the upstream side of the supercooling release device and melting the ice to prevent its growth and progress, there is a loss in energy, It is not very preferable, and as disclosed in Patent Document 2, ice water at 0 [° C.] from the small-diameter pipe provided on the inlet side of the supercooling release device has a flow velocity in the pipe of a predetermined value or more. In this way, the ice is peeled off by the fluid force, and the phase change from the supercooling water to the ice is prevented from propagating upstream, which has a problem that the structure becomes complicated. .

  In view of such circumstances, the present invention can make it difficult to attach ice to the upstream piping of the supercooling release device without reducing efficiency or complicating the structure. Providing a method for preventing the propagation of ice adhering to the wall, which can make it easier to peel off, prevent the growth and progress of ice in the upstream piping of the supercooling release device, and stabilize the continuous operation of the system It is something to try.

The present invention manufactures ice water below the freezing point by releasing the supercooling of the heat storage material cooled to the supercooled state by the supercooler and storing it in the ice water heat storage tank, and storing it in the ice water heat storage tank. A method of preventing the propagation of ice adhering to the wall surface by taking out the frozen ice water and using it as a cold heat source,
A progress preventing film for preventing the growth and progress of the supercooling heat storage material flowing through the pipe is formed on at least the inner surface of the pipe for introducing the supercooling heat storage material into the supercooling release device. The present invention relates to a method for preventing propagation of wall-attached ice, wherein the operation is performed so that the flow velocity does not become less than a preset lower limit value.

  According to the above means, the following operation can be obtained.

  As described above, a progress preventing film is formed on at least the inner surface of the pipe for introducing the supercooling heat storage material to the supercooling release device, thereby preventing the growth and progress of ice by preventing the adhesion of ice, and the supercooling flowing in the pipe If the operation is performed so that the flow rate of the heat storage material does not become less than the preset lower limit value, it is difficult for ice to adhere to the upstream piping of the supercooling release device. The growth and progress of ice to the upstream piping of the cooling release device is surely prevented, and there is no concern that the supercooler is blocked, and the continuous operation of the system is not hindered.

  And, as disclosed in Patent Document 1, the growth / progress is not prevented by heating the outside of the pipe on the upstream side of the supercooling release device and melting the ice, so there is a loss in energy. In addition, as disclosed in Patent Document 2, 0 [° C.] ice water is injected from a small-diameter pipe provided on the inlet side of the supercooling release device so that the flow velocity in the pipe becomes a predetermined value or more. Therefore, there is no concern that the structure becomes complicated as compared with the case where the ice is separated by fluid force and the phase change from the supercooling water to the ice is prevented from propagating upstream.

  In the method of preventing propagation of wall-attached ice, the progress preventing film can be formed by applying a silicone-modified fluororesin.

  In the method for preventing propagation of ice on the wall surface, the progress preventing film may be formed by processing a plating film having innumerable fine protrusions formed on the surface of the fluororesin and having water repellency.

  Furthermore, in the method for preventing propagation of wall-attached ice, the lower limit value of the flow rate of the supercooled heat storage material flowing in the pipe can be set to 4 [m / sec].

  According to the method for preventing propagation of wall-attached ice of the present invention, it is possible to make it difficult for ice to adhere to the upstream piping of the supercooling release device without reducing efficiency or complicating the structure, Even if it adheres, the ice can be easily peeled off, and it is possible to prevent the ice from growing and progressing to the upstream piping of the supercooling release device, and to stabilize the continuous operation of the system. Can play.

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

  FIG. 1 is an example of an embodiment for carrying out the present invention. In the figure, the parts denoted by the same reference numerals as those in FIGS. 4 to 6 represent the same thing, and a supercooling heat storage material is applied to the supercooling release device 3. A progress preventing film 16 for preventing the growth and progress of the supercooled heat storage material introduction nozzle 12 as a pipe to be introduced is formed on the at least inner surface of the supercooling heat storage material introduction nozzle 12 as the pipe. The operation is performed so that the flow velocity V of the supercooling heat storage material flowing inside does not become less than a preset lower limit value.

  Here, FIG. 2 shows the results of tests performed under different conditions in order to demonstrate the effect of preventing the growth and progress of ice in an example of the embodiment of the present invention.

  No. 1, a supercooled heat storage material introduction nozzle 12 made of ethylene trifluoride chlorinated resin having an inner diameter D of 50 A and a length L of 100 mm was used, and the flow rate V of the supercooled heat storage material was set to 5.6 [m / s]. When the degree of cooling was −1.0 [° C.] (1.0 deg), it was confirmed that ice attached to the supercooled heat storage material introduction nozzle 12 grew and progressed over the entire length of the nozzle.

  No. 2 using a supercooled heat storage material introduction nozzle 12 made of ethylene trifluoride chlorinated resin having an inner diameter D of 40 A and a length L of 100 mm, and the flow rate V of the supercooled heat storage material is set to 7.5 [m / s] Even when the degree of cooling was −0.5 [° C.] (0.5 deg), it was confirmed that the ice attached to the supercooled heat storage material introduction nozzle 12 grew and progressed over the entire length of the nozzle.

  No. 3 using a supercooling heat storage material introduction nozzle 12 in which a silicone-modified fluororesin is formed on a transparent vinyl chloride base material having an inner diameter D of 50 A and a length L of 200 mm to form a progress prevention film 16. When the flow velocity V of the material is 5.6 [m / s] and the degree of supercooling is −1.9 [° C.] (1.9 deg), ice does not adhere to the supercooled heat storage material introduction nozzle 12 and the total length of the nozzle It was confirmed that there was no growth or progress over the entire period. When the silicone-modified fluororesin is applied to the transparent vinyl chloride base material to form the progress preventing film 16, the silicone-modified fluororesin is applied so that there is no defect area and air bubbles and dust are not trapped. However, care was taken so that the progress prevention film 16 was not uneven. Under the same conditions, when the degree of supercooling is −2.0 [° C.] (2.0 deg), ice adheres to the supercooled heat storage material introduction nozzle 12, but ice grows and progresses 120mm upstream from the nozzle tip. Was stopped, and it was confirmed that this state could be maintained for 3 hours. Further, it was confirmed that substantially the same result was obtained even when the flow velocity V of the supercooled heat storage material was lowered to 4.0 [m / s].

  No. 4, a supercooled heat storage material introduction nozzle 12 in which a special modified silicone is applied to a transparent vinyl chloride base material having an inner diameter D: 50A and a length L: 200 mm to form a progress prevention film 16 is used. When the flow velocity V is 5.6 [m / s] and the degree of supercooling is −1.3 [° C.] (1.3 deg), the ice adhering to the supercooled heat storage material introduction nozzle 12 extends over the entire length of the nozzle. It was confirmed that it would grow and progress. When the specially modified silicone is applied to the transparent vinyl chloride base material to form the progress preventing film 16, the specially modified silicone is applied so that there is no defect area and air bubbles and dust are not trapped. Care was taken not to make the film 16 uneven.

  No. 5, a Pyrex (registered trademark) glass-made supercooled heat storage material introduction nozzle 12 having an inner diameter D of 50 A and a length L of 200 mm was used, and the flow rate V of the supercooled heat storage material was set to 5.6 [m / s]. When the degree of cooling was −0.5 [° C.] (0.5 deg), it was confirmed that the ice attached to the supercooled heat storage material introduction nozzle 12 grew and progressed over the entire length of the nozzle.

  No. No. 6 is a transparent vinyl chloride base material having an inner diameter D of 50A and a length L of 200 mm, and a plating film (super water-repellent electroplating film) having numerous fine protrusions formed on the surface of the fluororesin and having water repellency. Using the supercooled heat storage material introduction nozzle 12 in which the progress preventing film 16 is formed by processing, the flow rate V of the supercooled heat storage material is set to 5.6 [m / s], and the degree of supercooling is −2.0 [° C.] (2 .0 deg), it was confirmed that ice does not adhere to the supercooling heat storage material introduction nozzle 12 and this state can be maintained for 2 hours and 40 minutes. Further, it was confirmed that substantially the same result was obtained even when the flow velocity V of the supercooled heat storage material was lowered to 4.0 [m / s].

  The outer peripheral surface of the tip 12a of the supercooling heat storage material introduction nozzle 12 is formed in a tapered shape with a gradient α of 15 °.

  Incidentally, the super-water-repellent electroplating film as the progress preventing film 16 is an infinite number of fine protrusions (PTFE) on the surface of a fluororesin such as tetrafluoroethylene (PTFE: polytetrafluoroethylene) as shown in FIG. A so-called fractal structure with a water-repellent plating film, and a contact angle θ, which is an angle formed by a contact portion of a water droplet formed on the surface, is about 170 °, which is very High water repellency can be obtained.

  Now, when considering the factors affecting the adhesion of ice, the factors include water repellency and surface roughness on the inner surface of the pipe. From the results of the above test, silicone having water repellency (No. 4 ) And fluororesin (see No. 1 and No. 2) alone have no effect of preventing ice growth and progress, and hydrophilic Pyrex (registered trademark) glass (see No. 5) with low surface roughness. It was found that ice growth and progress could not be prevented.

  Thus, in the ice heat storage system, water repellency is more important than the surface roughness of the progress preventing film 16 for preventing ice growth and progress between the supercooling release device 3 and the supercooler 2, but It turns out that the growth and progress of ice cannot be prevented only with an aqueous material, and a silicone-modified fluororesin is applied to form a progress prevention film 16 (see No. 3) or the surface of the fluororesin is innumerable. It is effective to form a progress preventing film 16 (see No. 6) by processing a plating film (super water-repellent electroplating film) having fine protrusions and having water repellency, which is clear from the above test results. It became.

  That is, as described above, the progress prevention that prevents the growth and progress of ice by suppressing the adhesion of ice to at least the inner surface of the supercooling heat storage material introduction nozzle 12 as a pipe for introducing the supercooling heat storage material to the supercooling release device 3. When the film 16 is formed and the operation is performed so that the flow velocity V of the supercooling heat storage material flowing through the supercooling heat storage material introduction nozzle 12 as the pipe does not become lower than a preset lower limit value, the upstream side of the supercooling release device 3 Ice becomes difficult to adhere to the pipe, and even if it is attached, the ice is easily peeled off, and the growth and progress of ice to the upstream pipe of the supercooling release device 3 is surely prevented, and the supercooler is blocked. The continuous operation of the system is not hindered.

  And, as disclosed in Patent Document 1, the growth / progress is not prevented by heating the outside of the pipe on the upstream side of the supercooling release device and melting the ice, so there is a loss in energy. In addition, as disclosed in Patent Document 2, 0 [° C.] ice water is injected from a small-diameter pipe provided on the inlet side of the supercooling release device so that the flow velocity in the pipe becomes a predetermined value or more. Therefore, there is no concern that the structure becomes complicated as compared with the case where the ice is separated by fluid force and the phase change from the supercooling water to the ice is prevented from propagating upstream.

  Thus, it is possible to make it difficult to attach ice to the upstream piping of the supercooling release device 3 without reducing efficiency or complicating the structure, and even if it adheres, the ice can be easily peeled off. It is possible to prevent the ice from growing and progressing to the upstream piping of the supercooling release device 3, and to stabilize the continuous operation of the system.

  It should be noted that the method for preventing the propagation of wall-attached ice according to the present invention is not limited to the above-described illustrated examples, and various modifications can be made without departing from the scope of the present invention.

It is sectional drawing which shows the supercooling heat storage material introduction | transduction nozzle in an example of embodiment which implements this invention. It is a figure which shows the test result performed by changing conditions in order to demonstrate the growth and progress prevention effect of ice in an example of embodiment which implements this invention. It is a conceptual diagram which shows the contact angle of the water droplet on the plating film which has the water repellency used in an example of embodiment which implements this invention. It is a schematic block diagram which shows an example of the ice heat storage system already developed. It is sectional drawing which shows an example of the supercooling cancellation | release apparatus used for the ice thermal storage system shown by FIG. It is VI-VI sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigeration unit 2 Supercooler 3 Supercooling cancellation | release apparatus 4 Ice water thermal storage tank 12 Supercooling thermal storage material introduction nozzle 12a Tip 16 Propagation prevention film D Inner diameter L Length α Gradient V Flow velocity θ Contact angle

Claims (4)

The heat storage material cooled to the supercooled state by the supercooler is released from the supercooling release device to produce the ice water below the freezing point and stored in the ice water heat storage tank, and the ice water stored in the ice water heat storage tank is stored in the ice water heat storage tank. It is a method for preventing the propagation of ice on the wall surface, which is taken out and used as a cold heat source,
A progress preventing film for preventing the growth and progress of the supercooling heat storage material flowing through the pipe is formed on at least the inner surface of the pipe for introducing the supercooling heat storage material into the supercooling release device. A method for preventing propagation of wall-attached ice, wherein the operation is performed so that the flow velocity does not fall below a preset lower limit value.   The method for preventing propagation of wall-attached ice according to claim 1, wherein the progress preventing film is formed by applying a silicone-modified fluororesin.   The method for preventing propagation of wall-attached ice according to claim 1, wherein the progress preventing film is formed by processing a plating film having innumerable fine protrusions formed on the surface of a fluororesin and having water repellency.   The method for preventing propagation of wall-attached ice according to any one of claims 1 to 3, wherein a lower limit value of a flow rate of the supercooled heat storage material flowing in the pipe is 4 [m / sec].

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