JPH10122610A - Ice storage device and its operating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent supercooled water from entering an ice water transporting pipe in an ice storage device. SOLUTION: A circulating pipe 9 for cold water 3 fed to a supercooler 10 at a temperature not lower than an icing point is provided with a bypass pipe 14. In the case wherein an icing operation releasing action in a supercooling releasing tank 12 is not operated well, right before supercooled water 3a enters a ice water transporting pipe 13, cold water of temperature exceeding an icing point is fed from the bypass pipe so as to heat the supercooled water 3a so as to generate a temperature difference across the releasing tank 12, a supercooled state releasing action is generated in the releasing tank 12 and the icing is prevented within the transporting pipe 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice refrigerating apparatus for producing ice water by using surplus electric power or other motive power at night, and utilizing the cold heat of the ice water for refrigeration of food, cooling in daytime, and the like. It relates to the driving method.

[0002]

2. Description of the Related Art In an ice regenerator, if the degree of supercooling of cold water supercooled by a subcooler becomes excessive, icing occurs in the subcooler or downstream thereof, and the operation must be stopped.

However, when the degree of supercooling is small, it is more difficult to spontaneously release the supercooling than when the degree of supercooling is appropriate or large, and a large amount of energy is required to start the release. In this case, at the stage where the supercooled water is discharged to the subcooling release tank, the release, that is, the phase change does not occur, and the release may be started gradually after reaching the small-diameter ice water transport pipe. When such a phenomenon occurs, ice is precipitated from the inner surface of the ice water transport pipe to the entire inside of the pipe and becomes frozen, and the flow of ice water is prevented, so that the operation must be stopped.

[0004] In particular, at the start of the ice making operation, no ice is deposited on the inner surface of the tank in the subcooling release tank or on a collision surface formed by a collision plate which may be separately provided, and ice is floating on the water surface. Therefore, no seed crystal, ie, an ice nucleus, which triggers release of the supercooled water flowing into the collision surface or the water surface does not exist. For this reason, the supercooled water cannot obtain enough energy to start the release, and icing may occur after flowing into the ice water transport pipe.

Conventionally, as means for preventing icing from occurring in a transfer pipe downstream of a subcooler, for example, Japanese Patent Laid-Open No.
The technique of JP 8066 is known. This technology detects the water temperature at the outlet of the subcooler, and when the water temperature falls within the freezing occurrence temperature range, lowers the cooling capacity of the supercooler to maintain the water temperature near the freezing point, and after a predetermined time elapses, the cooling capacity Is trying to recover. However, since this conventional technique controls the cooling capacity of the subcooler, the control means must be complicated, and a subcooling release tank is provided downstream of the subcooler. In order to prevent icing downstream of the supercooling release tank, the apparatus provided with the above cannot be used as it is.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a technique in which a subcooling release tank is provided downstream of a subcooler, wherein the supercooling is released when the degree of supercooling of the supercooling water is small or at the start of operation. It is an object to prevent the supercooling water from being released from the supercooled water in the ice water transport pipe when no ice is generated in the tank.

[0007]

According to one aspect of the present invention, there is provided an ice storage tank for storing ice water, and recirculation of cold water in the ice storage tank. A supercooler for supercooling the supercooled water, a subcooling release tank for receiving the supercooled water discharged from the subcooler, and an ice water transport pipe for sending ice water generated in the subcooling release tank to the ice storage tank. The ice cool storage device according to claim 1, wherein a heating device for heating supercooled water passing through the ice water transfer tube is provided upstream of the ice water transfer tube.

According to this means, when the supercooled water flowing into the ice water transport pipe is heated by the heating device provided on the upstream side of the ice water transport pipe, the rate at which the supercool release is generated in the supercool release tank is reduced. A phenomenon of increasing the temperature occurs, and at the same time, the temperature of the supercooled water rises due to the heating, so that icing in the ice water transport pipe is prevented.

According to a second aspect of the present invention, as described in the second aspect, in the first aspect, chilled water in an ice storage tank is used as a heat source of the heating device, and the chilled water is transferred through an injection pipe. An ice regenerator characterized by joining supercooled water in a pipe and heating the supercooled water. According to this means, since the cold water in the ice storage tank has a temperature above the freezing point,
By mixing a small amount of the cold water with the supercooled water flowing into the ice water transfer pipe, the supercooled water is heated and no ice is generated.

According to a third aspect of the present invention, as set forth in the third aspect, in the second aspect, a plurality of sets of a subcooler and a subcooling release tank are arranged in parallel, and one of the sets is stopped and stored. One of a plurality of supercooling systems characterized by heating the supercooled water by joining the supercooled water in the ice water transport pipe through the set of supercooled release tanks in which the cold water in the ice tank is suspended. Since the heating source can be obtained by stopping the operation, it is not necessary to provide a water passage for heating.

According to a fourth aspect of the present invention, there is provided an ice cold storage device according to the first, second, third or fourth aspect.
A method for operating an ice regenerator, characterized in that the heating device is operated immediately after the start of the subcooler, when there is no ice in the subcooling release tank. According to this means, at the start of the operation of the subcooler, icing in the ice water transfer pipe, which is likely to occur because no ice nuclei are generated in the subcooling release tank, is prevented.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is an ice regenerator of the present invention, 2 is an ice storage tank, in which ice water 5 in which cold water 3 and small pieces of ice 4 are mixed is stored, and the cold water 3 is pumped. At 6, it is sent to a load device 7 provided outside for use in refrigeration or cooling of food.

When there is surplus electric power such as at night, the supercooling system 1a including the refrigerator 11 is operated, and the cold water 3 is sent to the supercooler 10 through the circulation pump 8 and the circulation pipe 9, and is cooled. It is supercooled by the brine cooled by the machine 11, becomes supercooled water 3 a of, for example, −2.0 ° C., is discharged to the subcooling release tank 12, and collides with the collision surface 12 a of the tank 12. As a result, the supercooling is released, and the ice 4 precipitates out to become ice water 5 in which small pieces of ice 4 are mixed in the cold water 3, and is returned to the ice storage tank 2 through the ice water transport pipe 13.

The above configuration is conventionally known,
The embodiment shown in FIG. 1 is characterized in that a bypass-shaped injection pipe 14 and a stop valve 15 communicating between the middle of the circulation pipe 9 and the upstream side of the ice water transport pipe 13 are provided, and the supercooled water 3a is provided. If the degree of supercooling is as small as about −0.1 ° C., it is difficult to release the supercooling. The supercooled water 3a is heated by mixing and returned to the ice storage tank 2 as 0 ° C. cold water. In this case, the portion on the upstream side of the ice water transport pipe 13 is a portion for increasing the temperature of the supercooled water 3a, and thus can be referred to as a heating unit 17 for the supercooled water 3a.

In this apparatus 1, when the supercooling system 1a is started, the chilled water 3 is gradually cooled by the subcooler 10 to become the supercooled water 3a and discharged to the subcooling release tank 12.
Since the degree of supercooling of the supercooled water 3a is small at first, a large amount of energy is required for release as described above, and the ice 18 does not precipitate on the collision surface 12a at the time of starting. It does not occur. Therefore, the supercooled water 3a
Flows through the area where no ice nuclei exist, and no supercooling is released.

However, even if the degree of subcooling is small, if the supercooled air is sent into the ice water transport pipe 13 and unexpectedly released in the transport pipe 13, the present invention is not limited to this. Is
As a result of exploring means for preventing this, the supercooled water 3a is heated near the inlet of the ice water transport pipe 13, and a temperature difference is generated between the upstream side and the downstream side where the downstream side has a slightly higher temperature. Even if the temperature on the side is below the freezing point, the rate of occurrence of release in the subcooling release tank 12 on the upstream side is increased, and it is found that freezing is hard to occur in the ice water transport pipe 13. If the downstream side is heated to a temperature above the freezing point, freezing on the downstream side does not occur naturally.

If the operation in this state is continued for a while after the start, the degree of supercooling of the supercooling water 3a entering the subcooling release tank 12 becomes large, so that the release in the release tank 12 starts to occur. Then, ice 4 and 18 are generated, and the releasing action due to the collision is promoted, so that the whole amount is released in the releasing tank 12. In this state, the stop valve 15 is closed to stop the mixing of the chilled water 3, and a steady operation is performed.

When the supercooled water 3a is at -0.1.degree. C. and the cold water is at + 2.5.degree. C., the amount of the cold water 3 injected downstream from the injection pipe 14 to heat the supercooled water 3a to the freezing point is as follows. In view of the amount of heat transfer, this is 4% of the total circulation amount.

However, even if the temperature of the water after being heated in the heating unit 17 is negative, if a temperature difference occurs between the temperature of the unheated portion upstream of the heating unit 17 and the temperature of the water, the excess temperature will It was found that the cooling release action easily occurred.

FIG. 2 shows an experimental device for the supercooling release action. The bottom of the supercooling release tank 12 having an inner diameter of 70 mm is tapered.
An ice water transfer pipe 13 having an inner diameter of 25 mm and a heating water injection pipe 14 are connected to the lower end thereof, and the end of the ice water transfer pipe 13 is connected to an outlet 13.
a is opened in a water receiving tank (not shown), and P is
This is a boundary point between the inside of the supercooling release tank 12 and the portion outside the release tank on the downstream side. T ₁ , T ₂ , T ₃ are temperature measurement positions and measured temperatures (° C.) at the positions, T ₁ is the temperature of the supercooled water in the release tank, T ₂ is the water temperature after mixing the heated water, and T ₃ is the temperature of the mixed water. At the temperature of the heating water, the supercooling release tank 12 is filled with the supercooled water 3a at a rate of 18 l / min.
Supplied.

FIG. 3 is a graph showing the results of an experiment performed by the apparatus of FIG. 2, in which the vertical axis represents the number of experiments N, and the horizontal axis represents the temperature difference T ₂ −T _1.
The number of occurrences of supercooling release in the release tank 12 is indicated by hatched bars, the number of occurrences outside the release tank 12 is indicated by vertical stripes, and the ratio of the number of occurrences in the release tank 12 to the total number is shown. Indicated by open bars. FIG. 3A shows T without heating.
₂ -The number of times of release and the release ratio when T ₁ = 0,
(B) shows that the temperature difference caused by heating is more than 0 ° C to 0.2 ° C, more than 0.2 ° C to 0.3 ° C, and so on every 0.1 ° C to 0.6 ° C. The location and the number of occurrences of release are shown separately, and (C) shows the total number of (B) and the ratio of those released in the release tank 12.

As apparent from FIG. 3A, T ₂ -T ₁
The release rate in the release tank when = 0 is 20%,
As shown in FIG. 3 (C), the release rate of the heated ones is 55% in the release tank. In this experimental example, if T ₂ -T ₁ is 0.3 ° C. or less, all the pieces are released in the release tank 12. doing.

Next, in the embodiment of FIG. 4, two sets of supercooling systems 20, 21 are provided in the ice regenerator 1, and the respective pipelines are opened and closed by stop valves 22, 23, 24. The supercooling systems 20 and 21 can operate independently.
In this apparatus 1, when one of the subcooling systems 20 is started, the refrigerator 11 is not operated in the other subcooling system 21, and the degree of subcooling of the supercooled water 3a flowing out of the one subcooling system 20 is small. In the subcooling system 21, the cold water 3 is allowed to flow through the subcooler 10 as it is, and the cold water 3
6 heats the supercooled water 3a that is injected into the ice water transport pipe 13 and exits the subcooling release tank 12 of the supercooling system 20. The icing prevention action in the ice water transport pipe 13 in this embodiment is the same as that in FIG. 1. If a temperature difference occurs in which the downstream side increases at the junction 16, the release ratio in the supercooling release tank 12 increases. Become.

In each of the above-described embodiments, means for mixing the cold water 3 is used for heating the supercooled water 3a in the ice water transport pipe 13. It may be heated by another heating means. For example, refrigerator 1
The heat generated by the first condenser may be used to heat the condenser from the outside.

[0025]

As is apparent from the above description, according to the first aspect of the present invention, when the supercooled water enters the ice water transfer pipe from the supercool release tank, the supercooled water in the ice water transfer pipe is removed. When heating is performed to cause a temperature difference between the supercooled water in the supercooling release tank and the supercooled water, the release in the release tank is promoted, and there is an effect that icing in the ice water transport pipe can be prevented.

According to the second aspect of the present invention, the heating can be performed only by adding the cold water in the ice regenerator to the supercooled water entering the ice water conveying pipe, and the structure is extremely simple and the operation can be switched quickly. There are benefits to crabs.

According to the third aspect of the present invention, in a device in which a plurality of supercooling systems are switched and used, the suspended supercooling system can be used for supplying cold water for heating, so that equipment costs are reduced. There is no advantage.

According to the fourth aspect of the present invention, the supercooling release effect on the supercooled water is low immediately after the start of the supercooling system. There are advantages.

[Brief description of the drawings]

FIG. 1 is a layout diagram of a first embodiment of the present invention.

FIG. 2 is a schematic diagram of an experimental device that has demonstrated the operation of the present invention.

FIG. 3 is a graph of numerical values obtained by the experimental apparatus of FIG.

FIG. 4 is a layout diagram of a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ice regenerator 1a, 20, 21 Supercooling system 2 Ice storage tank 3 Cold water 3a Supercooled water 4,18 Ice 5 Ice water 9 Circulation pipe 10 Supercooler 11 Refrigerator 12 Supercool release tank 13 Ice water conveyance pipe 14 Bypass pipe 16 Confluence 17 Heating

Claims (4)

[Claims] 1. An ice storage tank for storing ice water, a supercooler for recirculating cold water in the ice storage tank to supercool, and a supercool release for receiving supercooled water discharged from the supercooler. In an ice regenerator including a tank and an ice water transfer pipe that sends ice water generated in the supercool release tank to an ice storage tank, the supercooled water passing through the ice water transfer pipe is heated upstream of the ice water transfer pipe. An ice cool storage device comprising a heating device. 2. The supercooled water according to claim 1, wherein cold water in an ice storage tank is used as a heat source of the heating device, and the cold water is combined with supercooled water in an ice water transport pipe via an injection pipe to heat the supercooled water. An ice regenerator characterized by the following. 3. The supercooling release of a set in which a plurality of sets of a supercooler and a subcooling release tank are arranged in parallel, one of which is stopped and the cold water in the ice storage tank is stopped. An ice regenerator characterized by heating the supercooled water by joining the supercooled water in an ice water transport pipe through a tank. 4. The ice regenerator according to claim 1, wherein the heating device is operated immediately after the subcooler is started and when there is no ice in the subcooling release tank. Cool storage device operation method.