JP2000274747A - Dynamic type ice storage system and its double pipe type heat-exchanger and supercooling release pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent suspension of ice making operation due to freezing and to perform operation at the proper degree of supercooling in a continuous and high ice making capacity state. SOLUTION: The temperature of cold water at the outlet of a heat-exchanger 2 of a supercooler 1 is detected and a flow rate of a water pump 4 to return cold water 3a to a supercooler 1 to an ice storage tank 3 is controlled according to the temperature of cold water. Further, the heat-exchanger 2 is a double pipe type heat-exchanger, and a supercooling release pipe 10 in which a floating body 11 is floated is situated below an outlet for supercooling cold water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic ice heat storage system and a double-pipe heat exchanger and a supercool release pipe.

[0002]

2. Description of the Related Art The present inventor has already filed Japanese Patent Application No. 8-236396.
Proposed a hybrid thermal storage device and its operation method. As such ice making devices, there are a supercooling device using a brine cooler and an ice-on-coil device. A subcooling device with a brine cooler is efficient, but becomes inoperable if its brine-water heat exchanger or refrigerant-water heat exchanger, i.e., the supercooler, freezes due to ice nuclei in the condensed water or mechanical stimulation. There is a drawback that the ice making operation must be interrupted and the ice melting circuit must be activated for the thawing. In other words, in dynamic ice heat storage using supercooled water,
Ice is created by releasing the cold water that has been cooled by the supercooler and causing supercooling, and ice is stored in the heat storage tank.However, part of the cold water in the heat storage tank is supercooled water or heat storage When part of the supercooled water flowing into the tank flows through the tank without releasing the supercooling, and flows out of the heat storage tank outlet and flows into the strainer or pump, part of the supercooled water becomes ice. Clogging and damage to the pump. Further, in making ice continuously by circulating cold water through the supercooler and the heat storage tank, if ice nuclei enter the supercooler, it causes freezing. Conventionally, the supercooled water is made into ice by hitting a fixed impact plate. However, it is not enough that the supercooled water becomes ice. There is a drawback that it flows into a strainer or a pump, where it freezes and becomes inoperable, and the ice making operation must be interrupted.

For example, in dynamic ice heat storage utilizing supercooled water, when cooling water into supercooled water by a brine-water heat exchanger, that is, a supercooler, a supercooler for producing supercooled water is used. To prevent ice nuclei from entering the cold water flowing into the, the nuclei are removed by raising the temperature above 0 ° C before flowing. Therefore, in order to flow cold water of 0 ° C. or more, and then convert the water into supercooled water of 0 ° C. or less in the supercooler, the sensible heat until the water is once cooled to 0 ° C. is also a load on the refrigerator. This load is an extra load for the refrigerator in making ice, and therefore, the temperature of the water is reduced to 0 in the load of the refrigerator.
It is desirable that the ratio of the load for setting the temperature to ° C be small. Therefore, it is desired to increase the degree of supercooling and reduce the ratio of the extra load. However, if the degree of subcooling is increased, the possibility of freezing in the subcooler increases as described above. If the ice is frozen in the subcooler, it is necessary to stop the ice making operation once and melt it by flowing high-temperature brine through the subcooler. Performance and coefficient of performance decrease significantly.

[0004] Therefore, it is desired to operate at an appropriate degree of supercooling, as continuously as possible, and with a large ice-making capacity.

[0005]

SUMMARY OF THE INVENTION The present invention is intended to prevent interruption of ice making operation due to freezing in the above-mentioned supercooling device. It is intended to drive.

[0006]

The present invention detects the temperature of chilled water at the outlet of the heat exchanger 2 of the subcooler 1 and returns the chilled water 3a from the ice storage tank 3 to the subcooler 1 based on the detected temperature. The dynamic ice heat storage system is characterized in that the flow rate of the pump 4 is controlled. The present invention also provides a dynamic ice heat storage system, comprising:
Is composed of an inner tube 5 and an outer tube 6, and a cooling brine from a refrigerator 7 flows in the inner tube 5 in one direction. Flow cold water 3a in the opposite direction,
The outlet of the supercooled water obtained by supercooling the cold water 3a between the inner pipe 5 and the outer pipe 6 is branched by a branch pipe 8, and the tapered surfaces 9a, 9
2. A double-pipe heat exchanger in a dynamic ice heat storage system according to claim 1, wherein a throttle nozzle 9 is formed through b, and cold water is returned from said nozzle 9 to said ice heat storage tank 3.

In the present invention, a subcooling release pipe 10 is provided below the outlet of the supercooled cold water 3a, and a floating body 11 is floated on the release pipe 10, and the supercooled water hits the floating body 11 and is supercooled. Is a supercooling release pipe in the dynamic ice heat storage system, characterized in that a part of the ice 3b is slurry-like.

[0008]

The cooling brine from the cold brine tank 21 flows in one direction by the pump 22, and the cold water 3a from the ice heat storage tank 3 flows between the inner pipe 5 and the outer pipe 6 in the opposite direction. The temperature detector 20 provided in the double-tube heat exchanger 2 detects the temperature of the cold water 3a, and controls the flow rate of the pump 23 so that the temperature becomes a set temperature that provides an appropriate degree of supercooling. . Thus, the supercooled water is supplied to the lower branch portion 8a of the branch pipe 8.
The supercooled water flows down into the supercooling release pipe 10 through the throttle nozzle 9 provided therein, and the supercooled water strikes the floating body 11 and receives an impact, and at the same time, a turbulent flow occurs, and the supercooling is easily released. It becomes slurry-like ice 3 b and flows down in the release pipe 10. The other part hits the inner wall of the release pipe 10 and becomes ice, and is discharged. However, it is scraped off by the vibration or rotation of the floating body 11 and becomes slurry-like ice 3b to flow down the release pipe 10, so that the release is performed. Clogging and freezing of the tube 10 can be prevented.

[0009]

FIG. 1 is an explanatory view schematically showing a dynamic ice heat storage system according to an embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view showing a main part of the double-pipe heat exchanger, and FIG. 3 is a cross-sectional view showing a process of forming the supercooled release pipe and ice.
As shown in FIG. 1, the heat exchanger 2 of the subcooler 1 is a double-pipe heat exchanger. The cold water 3 a in the ice heat storage tank 3 is supplied to the double-pipe heat exchanger 2 by the pump 4. The pump 4 is controlled by an inverter.

The outlet 25 of the double tube heat exchanger 2 has cold water 3
A temperature detector 20 (a copper ring of a thermocouple for measurement) made of a resistor having a temperature of a is provided. The temperature detector 20 is the subcooler 1
The temperature of the cold water 3a at the outlet of the heat exchanger 2 is detected, and the temperature signal 24 controls the flow rate of the water pump 4 that returns the cold water 3a from the ice heat storage tank 3 to the supercooler 1. As shown in FIG. 2, the double-pipe heat exchanger 2 comprises an inner pipe 5 and an outer pipe 6, wherein the inner pipe 5 is a stainless steel flexible tube, and the outer pipe 6 is a vinyl chloride tube or an acrylic resin tube. is there. Cooling brine from a cold brine tank 21 provided in the refrigerator 7 is flowed into the inner pipe 5 in one direction (left side in FIG. 1) by the pump 22.
In the space between the outer pump 6 and the cold water 3 from the water pump 4
a in the opposite direction (to the right in FIG. 1).

As shown in FIG. 2, a branch pipe 8 is connected to the end of the outer pipe 6, and the supercooled water outlet 25 of the cold water inner pipe 5 between the inner pipe 5 and the outer pipe 6 is connected to the branch pipe. A branch nozzle 8 is formed in the lower branch portion 8a of the branch pipe 8 through a first conical tapered surface 9a and a second conical tapered surface 9b. Then, the lower end of the nozzle 9 is pointed and is made to face a subcooling release pipe 10 shown in FIG.

As shown in FIG. 3, a floating body 11 such as a ping-pong ball is floated in the release pipe 10 and
Is curved in a U-shape in the cold water 3a in the ice heat storage tank 3, and is opened above the surface of the cold water 3a in the ice heat storage tank 3. Next, the operation of the apparatus of the present invention will be described with reference to FIG. Cooling brine from the cold brine tank 21 flows in one direction (left side in FIG. 1) by the pump 22, and between the inner pipe 5 and the outer pipe 6, the cold water 3 a from the ice heat storage tank 3 is supplied by the water pump 4. It flows in the opposite direction (to the right in FIG. 1) and is cooled. If the temperature of the supercooled water at the outlet 25 of the double-pipe heat exchanger 2 drops below the set temperature during the ice making, the inverter operates the pump 4.
When the temperature of the supercooled water at the outlet 25 is higher than the set temperature, the inverter operates the water pump 4 to increase the temperature of the supercooled water at the outlet 25. The frequency of the current is reduced and the outlet 25
, The temperature of the supercooled water at the outlet 25 is kept substantially constant. That is, the double tube heat exchanger 2
The temperature detector 20 provided at the outlet 25 detects the temperature of the cold water 3a, and controls the flow rate of the water pump 4 during ice making so that the temperature becomes a set temperature that gives an appropriate degree of supercooling.

If chilled water is supplied to the subcooler 1 at a constant flow rate, if the degree of supercooling at the subcooler outlet 25 is to be maintained at a certain temperature, if the capacity of the refrigerator is too large, some control is performed. If not, the degree of supercooling becomes too large, and the predetermined temperature cannot be maintained. On the other hand, as a control method, there is a method of controlling the temperature on the brine side to be sent to the subcooler, but in any case, if the capacity of the refrigerator is too large, the refrigerator cannot be continuously operated.

However, in the case of the present invention, when the refrigeration capacity is too large for a certain flow rate of the chilled water and the degree of supercooling becomes too large than the set temperature, the flow rate of the chilled water automatically increases, and therefore, the water temperature increases. As the temperature rises, the degree of supercooling is maintained at an appropriate subcooling set temperature. by this,
Since the cold brine tank can be omitted and a control mechanism for controlling the brine temperature is not required, the apparatus can be simplified.

[0015] Next, as shown in FIG.
5 through a throttle nozzle 9 provided in a lower branch portion 8a of the branch pipe 8 from the supercooling release pipe 1 shown in FIG.
However, since the lower end of the nozzle 9 is sharp, water hardly adheres to the outer surface of the tip. The supercooled water flowing down from the nozzle 9 hits the floating body 11 and receives a shock, and at the same time, a turbulent flow occurs, and the supercooling is easily released, and a part of the water becomes slurry-like ice 3 b and flows down in the release pipe 10. . The other part hits the inner wall of the release tube 10 and precipitates as ice, but is scraped off by the vibration or rotation of the floating body 11 such as a ping-pong ball, and the slurry ice 3b flows down in the release tube 10. Therefore, clogging and freezing of the release tube 10 can be prevented.

That is, when the release pipe is used, when the supercooled water flowing into the release pipe hits the floating body 11 such as a ping-pong ball, it is shocked and turbulent, and the supercooling is easily released. At this time, ice also precipitates on the inner wall of the release tube, but in the case of the present invention, the floating body 11 such as a ping-pong ball vibrates or rotates under the force of falling water. Serves to scrape off the ice on the wall of the tube,
Water will not be difficult to flow and freezing will not occur in the release tube.

Next, as shown in FIG.
Flows toward the top of the U-shaped release pipe 10 and overflows from the upper end of the release pipe 10 into the ice heat storage tank 3, and part of the ice grows and floats as an ice block 3 e, and other supercooled The water returns to the cold water 3a.

[0018]

As described above, according to the first aspect of the present invention, the temperature of the cold water 3a at the outlet of the heat exchanger 2 of the subcooler 1 is detected, and the temperature is transferred from the ice heat storage tank 3 to the subcooler 1 based on the detected temperature. Since the flow rate of the water pump 4 for returning the cold water 3a is controlled, the degree of supercooling of the supercooled water is maintained at a constant set temperature,
Freezing in the strainer or the pump can be prevented, interruption of the ice making operation can be prevented, and control of the cooling brine from the cold brine tank 21 provided in the refrigerator 7 becomes unnecessary, and in some cases, the cold brine tank 21 can be omitted. Things.

A second aspect of the present invention is the dynamic ice heat storage system, wherein the heat exchanger 2 of the subcooler 1 comprises an inner tube 5 and an outer tube 6, and the inner tube 5 includes a refrigerator 7. The cooling brine is flowed in one direction, the cold water flows in the opposite direction between the inner pipe 5 and the outer pipe 6, and the supercooled water of the cold water inner pipe 5 between the inner pipe 5 and the outer pipe 6. Is branched by a branch pipe 8 to form a squeezing nozzle 9 via a tapered surface, and the cold water is returned from the nozzle 9 to the ice heat storage tank 3. It is difficult to adhere.

Furthermore, the third aspect of the present invention relates to supercooled cold water 3a.
A release pipe 10 for supercooling is provided below the outlet of the container, and a floating body 11 is floated in the release pipe 10 and supercooled water is supplied to the floating body 11.
To release the supercooling to form slurry-like ice. The ice deposited on the wall of the release pipe 10 is scraped off by the vibration or rotation of the floating body 11 to flow down as slurry-like ice, and the clogging of the release pipe 10 is prevented. It can prevent freezing.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a dynamic ice heat storage system according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the double-pipe heat exchanger.

FIG. 3 is a cross-sectional view showing a process in which the supercooling release tube and ice are formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Subcooler 2 Heat exchanger 3 Ice heat storage tank 3a Cold water 4 Water pump 5 Inner tube 6 Outer tube 7 Refrigerator 8 Branch tube 9a Tapered surface 9b Tapered surface 9 Restrictor nozzle 10 Release tube 11 Floating body

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tadashi Sakakibara 2-29-17 Minamimagome, Ota-ku, Tokyo F-term in Ryosei Kogyo Co., Ltd. 3L054 BG04 BH03

Claims (3)

[Claims] The temperature of chilled water at an outlet of a heat exchanger (2) of a subcooler (1) is detected, and the temperature of the chilled water is transferred from an ice heat storage tank (3) to the subcooler (1) based on the detected temperature. A dynamic ice heat storage system, characterized in that the flow rate of a water pump (4) for returning pressure is controlled. 2. The dynamic ice storage system according to claim 1, wherein the heat exchanger (2) of the subcooler (1) comprises an inner pipe (5) and an outer pipe (6). Refrigerator (7)
The cooling brine is flowed in one direction, the cold water (3a) flows in the opposite direction between the inner pipe (5) and the outer pipe (6), and the inner pipe (5) and the outer pipe (6) The cold water (3a) during
The outlet of the supercooled water in the supercooled water inner pipe (5) obtained by subcooling the water is branched by a branch pipe (8) to form a throttle nozzle (9) through tapered surfaces (9a, 9b). The double-pipe heat exchanger in the dynamic ice heat storage system according to claim 1, wherein the cold water (3a) is returned to the ice heat storage tank (3) from the step (9). 3. A subcooling release pipe (10) is provided below the outlet of the supercooled cold water (3a), and a floating body (11) is floated in the release pipe (10), and the supercooled water (3) is floated. 3a) A supercooling release pipe in a dynamic ice heat storage system, wherein the supercooling is released by hitting the floating body (11) and a part of the ice is slurry.