JP2985070B2 - Ice making equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice manufacturing system for storing ice for heat storage as a cold heat source for air conditioning, ice for distribution for indoor and outdoor ski resorts, and ice for general cooling and cooling. The present invention relates to an apparatus for continuously and stably producing ice in a closed system using supercooled water.

[0002]

2. Description of the Related Art Apparatus for producing flocculent (sherbet-like / liquid-like) ice from supercooled water obtained by cooling water to 0 ° C. or less is well known. As a cooler for cooling water to 0 ° C. or less, a shell-and-tube type has been mainly used.

[0003] The present invention is intended to stably produce ice by employing a plate-type heat exchanger as a cooler to continuously change supercooled water into ice in a closed system. There are two ways to achieve this: stable generation of supercooled water, and stable transport of a mixture of water and ice (sorbet ice) generated after the supercooling is released.
One process is an important point.

(A) Step of stably generating supercooled water In order to prevent freezing of the supercooled water in the cooler and to stably generate the supercooled water, the water in the water-side flow path of the cooler must be provided. It is a known fact that the flow condition of water (supercooled water) and the temperature of supercooled water are important factors. The supercooled water temperature in this case indicates the lowest local temperature of the supercooled water in the heat exchanger, and is replaced by the surface temperature on the water flow path side on the cooling surface of a general cooler, It is not the temperature of the supercooled water itself discharged from the heat exchanger. In other words, if the flow condition of the supercooled water is constant, by setting the surface temperature on the water flow path side on the cooling surface to a certain temperature or higher,
Supercooled water can be generated stably.

[0005] From these facts, a conventional control method for stably generating supercooled water employs a method of controlling the temperature of a refrigerant (brine or the like) supplied to a heat exchanger. For example, in Japanese Patent Application Laid-Open No. 1-114682, in a supercooled water ice making system using a shell-and-tube heat exchanger, the water supply surface temperature is controlled to be -5.8 ° C to 0 ° C by controlling the brine supply temperature. By doing so, supercooled water can be generated stably. Japanese Patent Laid-Open No. 5-240
In a system using a plate-type heat exchanger as disclosed in Japanese Patent No. 474, it is said that a condition for stably generating supercooled water is affected by a flow ratio of water flowing through an inter-plate flow path and brine. From a subjective point of view, the flow rate ratio of water / brine in the plate flow path is indirectly detected by a flow meter, and the temperature of the brine supplied to the plate heat exchanger is set to -7 ° C to -4 ° C by the change in the flow rate ratio. A complicated control method of controlling as a lower limit is adopted.

However, these control methods depend on the temperature of the generated supercooled water itself, and when the water flow rate and the brine flow rate fluctuate, the supercooled water temperature fluctuates. If the vessel is used as a cooler,
Due to the structure of the plate heat exchanger, freezing occurs not only due to the supply temperature of the brine to be cooled, but also due to a drop in the supercooling water temperature itself. (2) When detecting the flow rate ratio, the number of sensing points is large and the control becomes complicated. (3) The amount of water generated from the supercooled water because the supercooled water temperature fluctuates. (4) The amount of heat exchanged by the heat exchanger (brine refrigeration load) fluctuates, so that the brine chiller cannot be operated steadily and the efficiency of the chiller is reduced.

[0007] In order to solve these problems, it is necessary to directly detect and control the temperature of the supercooled water. Therefore, it was difficult to directly measure the temperature of the supercooled water. In other words, even if the temperature sensor is mounted in the open-to-atmosphere state, the sensor itself plays the role of a shock plate, so the supercooled state is broken at the sensor part,
Since ice is generated, the temperature is 0 ° C., and the temperature of the supercooled water cannot be measured. Therefore, in practice, the temperature of the supercooled water has not been directly measured and controlled.

(B) Step of stably transporting a mixture of water and ice An ice making apparatus using supercooled water is disclosed in Japanese Patent Application Laid-Open No. 62-14727.
No. 1, JP-A-63-14063, JP-A-63-214
No. 63, as disclosed in JP-A-1-114682, the supercooled water generated by the cooler is discharged into the atmosphere from the cooler outlet, and is discharged to a collision plate or the like installed in the upper part of the heat storage tank below the cooler outlet. The supercooled state is eliminated by the collision, and sherbet ice is generated. Further, Japanese Patent Application Laid-Open No. 6-123
No. 455 and Japanese Patent Application Laid-Open No. 6-123456, supercooled water released to the atmosphere is received by a vertical pipe called a release pipe, and the supercooled state is eliminated in the release pipe. Is transferred to the heat storage tank by piping.

However, according to these methods, (1) a certain vertical distance or more is required between the cooler and the impact plate or the release pipe, and the height at which the apparatus is installed is limited. There is a spatial limitation between the heat storage tank that stores the ice and the cooler. (3) Heat is exchanged with the atmosphere because it is once released to the atmosphere, and some of the generated ice melts. (4) Freedom Since ice storage and ice conveyance are performed by falling and water level difference, there is a problem that it is difficult to convey generated ice to a distant place.

The present inventors have proposed a device for continuously converting supercooled water obtained by first cooling water to 0 ° C. or less into sherbet ice in a closed system as disclosed in Japanese Patent Laid-Open No. 7-48.
No. 01 and Japanese Patent Application Laid-Open No. H8-110133 have been proposed. With these devices, the sherbet ice generated from the supercooled water can be pumped by a pipe, and a supercooled ice manufacturing device having no height and space limitation can be realized.

However, the sherbet ice produced from the supercooled water is different from the sherbet ice produced by mixing antifreeze or the like, the sherbet ice produced by scraping the ice produced on the cooling surface, the plate ice, and the like. 1) The pipe immediately after the ice is formed is cooled to the supercooled water temperature at the time when the supercooled state is eliminated, and the generated ice easily adheres to the wall surface. (2) The ice generated from the supercooled water is It has needle-like and plate-like shapes, and has properties such as easy attachment to steps and projections on the inner surface of the transfer pipe. Pipes for transferring sherbet ice generated from supercooled water (hereinafter referred to as ice-water transfer pipes) It was found that there is a possibility of occlusion.

[0012]

SUMMARY OF THE INVENTION A first object of the present invention is to directly control the temperature of supercooled water and to produce supercooled water of a constant temperature easily and stably for a long time. It is to provide a device. Another object of the present invention is to provide an ice manufacturing apparatus capable of stably transporting sherbet ice generated from supercooled water so as not to be blocked in a pipe.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cooler for cooling water taken from a heat storage tank to produce supercooled water, and to eliminate the supercooled state of the generated supercooled water. A supercooling release device that converts water and ice into a mixture of water and ice is connected so that the water and ice flowing inside do not come into contact with the atmosphere, and the water is continuously converted to a mixture of water and ice in a closed system. In the ice making device which is stored in the heat storage tank,
A means for heating water taken from the heat storage tank to a temperature exceeding 0 ° C .; and a pipe for supplying the heated water to the cooler through an ice nucleus removing filter, wherein the cooler is a plate-type heat exchanger. The supercooled water transport pipe connecting the outlet of the plate type heat exchanger and the inlet of the supercooling release device is provided with a temperature sensor attached below the center in the horizontal direction, from the refrigerator. The plate type heat exchange
By adjusting the brine temperature sent to the heat exchanger,
This is achieved by an ice making apparatus that generates supercooled water and ice in a closed system while controlling the temperature of the supercooled water in the supercooled water transport pipe to be −3 ° C. to less than 0 ° C.

The plate type heat exchanger is adopted as the cooler because the number and size of the plates can be adjusted to flexibly cope with the flow rate, the physical properties of the fluid, the pressure loss, etc. This is because an optimum ice producing device can be provided according to the heat load.

As described above, in the conventional ice making apparatus, the supercooled water is immediately released to the atmosphere and changed into ice, so that even if a temperature sensor is attached, 0 ° C. is displayed, and it is meaningless. And the temperature sensor of the supercooled water was not attached. The present invention is an apparatus for producing ice in a closed system, and since the subcooling release device is disposed on the outlet side of the supercooled water, the outlet of the plate heat exchanger and the inlet of the subcooling release device are connected. Attaching a temperature sensor to the connected supercooled water transport pipe enabled effective measurement.

This temperature sensor is mounted so as to be located below the horizontal center of the supercooled water transport pipe, so that even if ice adheres between the temperature sensor and the branch pipe for inserting the temperature sensor, the specific gravity of the temperature sensor is kept low. It is set up so that ice floats up and is discharged upwards by the difference.

More preferably, the temperature sensor is tightly inserted into the inside of the subcooling water transfer tube via a resilient columnar resin sleeve inserted into the branch tube protruding from the supercooled water transfer tube without any gap. Is desirable.

As a further preferred embodiment, the inside of the supercooled water transfer pipe is lined with a resin paint (PVC, acrylic, etc.) having a small thermal conductivity and heat capacity, and the supercooled water is frozen in the supercooled water transfer pipe. So that a stable operating state can be maintained.

As a further preferred embodiment, a large curved pipe is connected to the outlet side of the subcooling release device so that the entire apparatus can be compactly housed in a room, and the large curved pipe has a bending radius of at least twice the pipe diameter. Smoothly curved, and furthermore, lining the inner surface of the pipe about 5 m downstream from the outlet of the supercooling release device with a resin-based paint to eliminate the blockage due to the mixture of water and ice, so that a stable operation state can be maintained. To

[0020]

According to the results of experiments conducted by the present inventors using an experimental apparatus using a plate-type heat exchanger, the conditions for stably producing supercooled water are as follows: (1) The water / brine flow rate ratio is completely Regardless, it is necessary to control the surface temperature of the water flow path side cooling surface (plate) to a constant temperature of -3.5 ° C. or more (from the structure of the plate heat exchanger, the cooling surface surface temperature can be regarded as the brine supply temperature). ).

(2) The collecting portion (hereinafter referred to as a header) of each fluid flow path outlet of the plate heat exchanger is not a smooth structure. In this case, the supercooled state is broken and freezing occurs, so that there is a lower limit value (-3.0 ° C.) of the supercooled water temperature that can flow through the header. Therefore, the result that the temperature of the supercooled water flowing out of the heat exchanger needs to be controlled to be constant at -3.0 ° C. as a lower limit value was obtained.

From these facts, the ice production system using the plate heat exchanger is not stable for the first time according to the present invention, which controls not only the brine temperature but also the supercooled water temperature as in the prior art. It was found that ice could be produced.

In the present invention, the cooler and the supercooling release device are sealed so that the water inside does not come into contact with the atmosphere, and ice is produced in a closed system. Because the vertical distance between the cooler and the heat storage tank (ice storage tank) is not sufficient, or for existing buildings where the heat storage tank is above the cooler, The installation of the manufacturing apparatus becomes possible. Also,
Since ice is produced in a closed system, dissolution of oxygen can be prevented, and deterioration of piping can be prevented.

In addition, since the supercooled water becomes a mixture of water and ice by the supercooling release device in the closed system and is transported in the pipe, the pressure of the water sent to the cooler is changed to the mixture of water and ice. It has the advantage that it can be transferred to any place through the pipe as it is.

In the subcooling canceling device in the ice making apparatus according to the present invention, a small-diameter pipe on the inlet side of the supercooled water is inserted into a large-diameter pipe on the outlet side as shown in, for example, JP-A-8-110133. The apparatus may be configured such that a phase change inducing device for inducing a phase change from supercooled water to ice is provided on the outer periphery of the large diameter pipe. In order to induce a phase change, the molecular arrangement of supercooled water is changed by using methods such as cavitation in water, collision or friction between solids in water, or strong turbulence in water. Provides the energy required for the part to have a stable ice structure.
Hereinafter, preferred embodiments according to the present invention will be described with reference to the accompanying drawings.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an experimental apparatus using a plate heat exchanger as a cooler will be described. FIG. 4 shows an experimental device for confirming the effect of the present invention. In this ice producing device, water in a heat storage tank 5 is heated to about 1 ° C. by a heater 6, and is continuously supplied by an ice making water circulation pump 7. After being supplied to the plate type heat exchanger 1 and cooled to a supercooled state in the plate type heat exchanger 1, it is transferred to the subcooling release device 3 through the supercooled water transport pipe 2, and The phase is changed to ice in the inside and becomes a mixture of ice and water. The mixture is transferred to the heat storage tank 5 through the ice water transport pipe 4, and the ice is stored in the heat storage tank 5.

The brine supplied to the plate heat exchanger 1 is cooled by a brine refrigerator 10 to an arbitrary temperature of -10 ° C. to −1 ° C., and is continuously supplied by a primary brine pump 11 and a secondary brine pump 13. Is done. Further, the temperature of the supercooled water is detected by a temperature sensor 16 installed in the supercooled water transport pipe 2 at the outlet of the plate heat exchanger 1, and the three-way valve 12 installed in the brine pipe is operated by the brine-side temperature controller 14. By doing so, the supercooling water temperature is controlled to an arbitrary temperature.

4, a manual valve 8, an ice nucleus removing filter 9, a water-side temperature controller 15, a water-intake-side temperature sensor 17, and brine temperature sensors 18 and 19 are further connected.

In the experiment, the conditions for stable generation of supercooled water by the plate-type heat exchanger were obtained by changing the flow rate of the ice making water supplied to the plate-type heat exchanger, the flow rate of the brine, and the supply temperature of the brine. Since the supercooled water freezes at the lowest temperature inside the heat exchanger, the surface temperature of the cooling plate on the water passage side of the cooling plate was calculated from the measured supercooled water temperature and the brine supply temperature and evaluated.

The calculation of the surface temperature is as follows: if the plate type heat exchanger is modeled as a parallel plate, the Prandtl number is 2/3.
Is proportional to the product of the power and the 4 / 5th power of the Reynolds number,
It was calculated by the following equation.

[0031]

Ts = Tb + (Tw−Tb) × Prw ^2/3 · R
ew ^4/5 / (Prw ^2/3・ Rew ^4/5 + Prb ^2/3・ R
eb ^4/5 )

Here, Ts is the surface temperature of the cooling plate on the water flow path side, Tb is the supply temperature of brine, Tw is the temperature of the supercooled water,
Prw is the Prandtl number of water, Rew is the Reynolds number in the plate-type heat exchanger channel of water, Prb is the Prandtl number of brine, and Reb is the Reynolds number in the plate-type heat exchanger channel of brine.

The supercooled state is an unstable state,
When the brine temperature that has been frozen by continuously lowering the brine temperature is taken as the freezing temperature, the condition under the cooling condition is an instantaneous state, and the operation is performed by increasing the brine temperature above the freezing temperature. However, since there is no guarantee that the supercooled water can be generated stably, in this experiment, after controlling the ice making flow rate, the brine flow rate, and the brine supply temperature to constant values, the operation was performed for at least 5 hours to freeze the freezing. The conditions were set such that the supercooled water could be stably generated only when the supercooled water could be produced stably without causing the water.

FIG. 6 shows the experimental results. The results show that when the brine flow rate is low, the plate surface temperature that causes freezing increases as the water flow rate increases, but when the brine flow rate increases, the surface temperature during freezing is almost constant regardless of the water flow rate. It turns out that it becomes. Although the calculation of the surface temperature is based on the theory of heat transfer of a parallel plate, the actual plate type heat exchanger has a corrugated plate as shown in FIG. Is water
And brine b flow alternately, but the heat transfer plate 21
It is conceivable that the actual water-side surface temperature of the plate contact portion 24 is locally low because the two are in contact at the apex of the wave shape.

That is, when the brine flow rate is reduced, the surface temperature is calculated to be higher.
It is considered that the freezing temperature is increasing on the graph because the temperature of the freezing point locally decreases. Similarly, when the amount of water is large, the freezing temperature is high when the amount of brine is small. Similarly, when the amount of water flow increases, the water side surface temperature approaches the temperature of water from the calculation. It is thought that it freezes.

In view of the above, an experiment was conducted by lining the apex portion 24 of the corrugated shape of the plate type heat exchanger shown in FIG. 5 with a resin paint to reduce the thermal conductivity of the plate contact portion 24. went. FIG. 7 shows the result. From this result, it can be seen that the water-side plate surface temperature causing freezing is lower than in the case where no lining is performed. This is because the plate contact portion 24 is provided with a resin-based lining having a low thermal conductivity, so that the contact portion 24 is formed.
This is because a decrease in temperature is prevented.

From these results, in order to stably generate supercooled water using the plate heat exchanger, the surface temperature of the water-side flow path of the plate was reduced by -3 regardless of the water / brine flow ratio. It has been found that freezing does not occur when the temperature is set to 0.5 ° C. or higher. Therefore, considering the local temperature drop at the plate contact portion, if the supply temperature of the brine itself is set to −3.5 ° C. or higher, the plate channel It is thought that freezing of the supercooled water in the inside can be prevented.

On the other hand, when the supercooled water freezes in the water-side flow path of the plate-type heat exchanger, the flow path is blocked by the generated ice, and the flow rate of the ice is instantaneously reduced. However, when supercooled water is generated using a plate-type heat exchanger, the ice making flow rate is maintained for 30 to 60 seconds even though ice is discharged (frozen) from the heat exchanger outlet. In some cases, the operation can be performed without lowering. This freezing form frequently occurs when the temperature of the supercooled water is lower than −3 ° C. this is,
It is considered to be a frozen form due to the structure of the plate heat exchanger.

That is, as shown in FIG. 5, when the supercooled water is generated by the plate-type heat exchanger, the water cooled in the plurality of inter-plate flow paths once merges into a space called the header 22, and Heat exchanger frame 2 through header 22
Since the supercooled water is discharged from the opening 25 opened at 0, the inside 22 of the header where the supercooled water flowing out from each inter-plate flow path merges has an exposed plate end, Since the structure is not smooth, it is considered that if the temperature of the supercooling water is too low, the supercooling state is broken due to the disturbance of the water flow flowing inside the header, and ice is generated inside the header 22.

However, even if ice is generated inside the header 22, it takes time until the phase change propagates to the inter-plate flow path and closes the plate, so that the ice making flow rate does not decrease during that time, and the plate type heat exchanger outlet Ice will be continuously discharged from the section. In other words, in order to continuously generate supercooled water using a plate heat exchanger while keeping it stable,
It has been found that it is necessary to prevent not only the freezing in the inter-plate flow path but also the freezing due to a drop in the supercooled water in the plate-type heat exchanger header 22. From this,
If the supercooled water temperature is controlled to a lower limit of −3 ° C., stable operation can be performed without freezing.

Further, when the supercooled water transport pipe 2 installed at the outlet of the plate type heat exchanger is constructed of a metal pipe, the above-mentioned freezing phenomenon was observed. This is because the supercooled state is eliminated by the influence of the inner surface roughness of the pipe, the connection projection due to welding, and the like. From this, when the inner surface of the supercooled water transfer pipe was lined with a resin-based paint to eliminate these protrusions, freezing in the supercooled water transfer pipe did not occur, and stable ice making operation could be performed. did it.

From the above experimental results, in order to generate supercooled water while maintaining a stable condition using the plate type heat exchanger as a cooler, (1) Freezing in the flow path between plates in the plate type heat exchanger (2) In order to prevent freezing at the header of the plate type heat exchanger, the temperature of the supercooled water should be -3.0 ° C or higher. Control,
It turned out to be necessary.

Further, as a result of the experiment, the temperature sensor attached to the supercooled water transfer pipe installed at the outlet of the plate type heat exchanger is connected to the branch pipe protruding from the supercooled water transfer pipe so that ice does not remain around the pipe. It has been found that a structure in which the sleeve is tightly inserted into the inside of the sleeve via a resilient cylindrical resin sleeve inserted without a gap is found. It has also been found that it is desirable to line the inside of the supercooled water transport pipe with a resin-based paint so as to eliminate the freezing of the supercooled water in the supercooled water transport pipe.

Further, experiments have revealed that the adhesion of ice when transporting ice water after the supercooling state is released occurs in a limited area. For example, when the diameter of the ice water transfer pipe is 100 A and the flow rate of the ice water is 2.0 m / s, the area within 5 m downstream of the subcooling release device is the area where the ice adheres. It was found that blockage could be prevented. In most cases where a large bent pipe is connected to the outlet side of the subcooling release device, if the bending radius of the large bent pipe is set to be twice or more the pipe diameter, the adhesion of ice is prevented and the pipe is not blocked. It was also found that ice water could be transported. Hereinafter, specific embodiments according to the present invention will be described with reference to the accompanying drawings.

[0045]

FIG. 1 shows an ice making apparatus embodying the present invention. This ice making device takes in water in a heat storage tank 5 with an ice making water circulation pump 7 and supplies the water to a plate heat exchanger 1 installed as a cooler. In the meantime, water taken from the heat storage tank 5 is cooled by the heating heat exchanger 29 installed between the plate heat exchanger 1 and the heat storage tank 5 by utilizing the cooling water of the refrigerator 10 or the like. 1 inlet water temperature is 0.5
The temperature is controlled by the two-way valve 28 so that the temperature becomes ° C. The connection with the heating heat exchanger 29 is performed by bypassing a part of the main flow from the outlet of the ice making water circulation pump 7, flowing into the heating heat exchanger 29, heating, and returning to the pump 7 inlet side again. The configuration is such that the 0 ° C. cold water from the heat storage tank 5 and the heated bypass flow are sufficiently mixed.

This method has the advantage that the heating heat exchanger 29 is more compact than the method in which the entire main flow is passed through the heating heat exchanger 29. On the other hand, in order to capture ice nuclei having a size that cannot be melted at 0.5 ° C., the ice nuclei are continuously supplied to the plate heat exchanger 1 through an ice nucleus removing filter 9 having a filtration diameter of 30 μm or less. Thus, the filter 9
Fine ice nuclei that have passed through are also completely removed and melted at 0.5 ° C.

The water from which the ice nuclei have been removed and melted is cooled to a supercooled state in the plate type heat exchanger 1 and then transferred to the ice making section through the supercooled water transport pipe 2, where the supercool release device 3 is provided. Inside, the supercooled water changes into ice to form a sherbet-like shape, is transferred into the heat storage tank 5 through the ice water transfer pipe 4, and the ice is stored in the heat storage tank 5.

The brine supplied to the plate heat exchanger 1 has a temperature of -3.5 ° C. or higher, which is a temperature at which the brine is not generated by the brine refrigerator 10 in the flow path between the cooling plates in the plate heat exchanger 1. After being cooled and controlled, it is continuously supplied to the plate heat exchanger 1 by a brine primary pump 11 and a brine secondary pump 13 through a brine supply pipe. Further, in order to prevent freezing inside the outlet header of the plate type heat exchanger, the temperature sensor 16 attached to the supercooled water transport pipe 2 so that the temperature of the supercooled water itself does not become −3.0 ° C. or lower. , The supercooling water temperature is directly detected, and control is performed by operating the three-way valve 12 attached to the brine supply pipe so that the supercooling water temperature becomes a constant temperature having a lower limit of −3.0 ° C.

Temperature sensor 1 for directly detecting supercooled water temperature
6 is mounted in a range 31 below the center in the horizontal direction so that ice does not remain on the sensor mounting portion as shown in FIGS. The mounting method is such that the branch pipe 30 is formed so as to protrude from the supercooled water transport pipe 2, and a resilient cylindrical resin sleeve 32 is inserted into the branch pipe 30 without any gap. Of the temperature sensor 16 is inserted without any gap. The sensor portion 16 </ b> A detects the temperature by protruding inward from the inner diameter of the supercooled water transport pipe 2.

Further, the inside of the supercooled water transport pipe 2 was lined with a resin-based paint so that freezing of the supercooled water in the supercooled water transport pipe was prevented. In addition, a lining pipe 27 was formed so as to prevent the blockage of the pipe by blocking the area 25 about 5 m downstream of the subcooling release device 3 of the ice water transport pipe 4. In addition, the bending radius of the large curved pipe 26 connected to the outlet side of the subcooling release device is set to be at least twice the pipe diameter. The ice water that has exited the lining pipe 27 is connected to a general pipe such as a metal pipe or a PVC pipe and transferred to the heat storage tank 5.

The supercool release device 3 is disclosed in
As shown in No. 33, a small-diameter pipe on the inlet side of the supercooled water is inserted into the large-diameter pipe on the outlet side, and a phase change induction is induced on the outer circumference of the large-diameter pipe to induce a phase change from supercooled water to ice. Although the device is configured as provided with the device, other similar devices can be used.

[0052]

As described above in detail, according to the present invention, the supercooled water temperature can be easily and stably generated for a long time by directly controlling the supercooled water temperature. An ice manufacturing apparatus is thus realized in which sherbet ice generated from the supercooled water is stably conveyed so as not to be clogged in the piping, and the technical effect is extremely remarkable.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an entire ice making apparatus according to the present invention.

FIG. 2 is a cross-sectional view of a temperature sensor attached to an outlet pipe of a plate-type heat exchanger.

FIG. 3 is an enlarged cross-sectional view illustrating a mounting portion of the temperature sensor.

FIG. 4 is a schematic diagram illustrating an entire experimental apparatus of the ice manufacturing apparatus.

FIG. 5 is a horizontal sectional view and a vertical sectional view of a plate-type heat exchanger.

FIG. 6 is a graph showing a state of stable generation of supercooled water by a plate-type heat exchanger.

FIG. 7 is the same graph as FIG. 6 when a lining is applied to a plate contact portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate-type heat exchanger 2 Supercooled water conveyance pipe 3 Supercooled release device 5 Heat storage tank 7, 11, 13 Pump 9 Ice nucleus removal filter 10 Brine refrigerator 12 Three-way valve 14, 15 Temperature controller 16, 17 Temperature sensor 26 Large curved pipe 27 Lining pipe 28 Two-way valve 29 Heat exchanger for heating

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-251177 (JP, A) JP-A-4-187921 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25C 1/00 F24F 5/00

Claims (4)

(57) [Claims] 1. A cooler for cooling water taken from a heat storage tank to produce supercooled water, and a supercooling release device for eliminating the supercooled state of the generated supercooled water and converting it into a mixture of water and ice. Is connected so that water and ice flowing therethrough do not come into contact with the atmosphere, and the water is continuously converted into a mixture of water and ice in a closed system and stored in a heat storage tank. Means for heating water taken from the heat storage tank to a temperature exceeding 0 ° C., and a pipe for supplying the heated water to the cooler through an ice nucleus removing filter, wherein the cooler is a plate-type heat exchanger. consists of exchanger, the supercooled water conveyance pipe for connecting the inlet of the outlet of the plate type heat exchanger subcooling release device, fitted with a temperature sensor so that the horizontal direction center positioned below, refrigerator Or
Adjusts the brine temperature sent to the plate heat exchanger.
An ice producing apparatus , wherein the supercooling water and the ice are generated while controlling the temperature of the supercooling water in the supercooling water transport pipe to be less than -3 ° C to less than 0 ° C. 2. The temperature sensor is tightly inserted inside the sleeve through a resilient cylindrical resin sleeve inserted without gap into a branch pipe protruding from the supercooled water transport pipe. The ice manufacturing apparatus according to claim 1. 3. The apparatus for producing ice according to claim 1, wherein the inside of the supercooled water transport pipe is lined with a resin-based paint to prevent freezing of the supercooled water in the supercooled water transport pipe. 4. A large curved pipe is connected to an outlet side of the supercooling release device, the large curved pipe has a bending radius of at least twice the pipe diameter, and is about 5 m downstream from the outlet of the supercooling release device.
2. The ice producing apparatus according to claim 1, wherein the inner surface of the pipe is lined with a resin-based paint to prevent freezing of a mixture of water and ice.