JP3270152B2 - Ice storage method - 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 heat storage method for storing heat source water for air conditioning in the form of coexistence with ice.

[0002]

2. Description of the Related Art When cooling and heating by circulating cold and hot water stored in a heat storage tank to a water-side heat exchanger of a fan coil unit and a water heat source heat pump unit disposed in a building, the cooling heat during cooling is stored. In recent years, a so-called ice heat storage system for storing ice in a tank has attracted particular attention because a small-scale device can store a large amount of cold heat. By the way, the ice stored in the heat storage tank in such an ice heat storage system is classified into an ice block type and a sherbet type according to the type of ice properties to be generated and used.
F (the filling rate of ice) can be increased, and the heat storage efficiency can be improved.

[0003] In producing such sherbet-like ice, for example, JP-A-63-217171, JP-A-63-231157, and JP-A-1-1468.
In the technology disclosed in Japanese Patent Laid-Open Publication No. 2 (1993) -210, a method and an apparatus for continuously generating supercooled water have already been proposed. According to these known techniques, the supercooled water is continuously discharged into the air from the discharge port of the heat transfer tube of the supercooler, and the discharged flow collides with a supercooling release unit such as a collision plate to apply an impact. Thereby, sherbet-like ice can be continuously and efficiently generated in a slurry state with water (ice / water slurry).

[0004] The subcooler used in the above technology is:
For example, a heat transfer tube through which water flows is disposed in a cooling container, and brine is passed through the refrigerator as a cooling medium in the cooling container, or the cooling container functions as an evaporator of a heat pump device. The superheated water of 0 ° C. or less is discharged from the discharge end of the heat transfer tube. Then, using the supercooler as described above, ice / water slurry is generated from water taken from the heat storage tank for storing the heat source water for air conditioning, and the slurry is supplied to the heat storage tank to store the ice / water in the heat storage tank. Since the ice heat storage method coexisting with water is extremely efficient, it has recently been widely used for air conditioning equipment such as buildings.

[0005] When water is taken from the heat storage tank in this way, the ice nuclei that have already coexisted with the water are taken in as they are and supplied to the subcooler. Flows in and the subcooler freezes. Therefore, when water is taken from the heat storage tank and supplied to the supercooler, it is necessary to prevent ice nuclei in the heat storage tank from flowing into the supercooler. In this respect, conventionally, for example, JP-A-3-2
As disclosed in JP-A-71643, JP-A-4-241251 and JP-A-4-8025, an ice filter is provided in the pipe between the heat storage tank and the supercooler, and the ice filter is Was to be collected. This ice filter uses, for example, a cylindrical cartridge type in which a cloth made of polyethylene or polypropylene is woven as a filter medium.

[0006]

However, in the above-mentioned prior art, there is a possibility that the pipeline may be blocked by clogging with dirt in the water. Also, the load on the pump cannot be ignored, and continuous operation may be difficult. In addition, there is a problem of durability of the filter itself, and maintenance is indispensable.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is capable of preventing ice nuclei from flowing into a supercooler without using a conventional ice filter. A method is provided to solve the above problem.

Therefore, in the first aspect, water taken from a heat storage tank for storing heat source water for air conditioning is supplied to a supercooler installed outside the heat storage tank, and supercooled discharged from the supercooler is provided. In the ice heat storage method in which ice / water slurry generated by water is supplied into the heat storage tank and ice / water coexists in the heat storage tank , a downward surface velocity in the heat storage tank is reduced.
Take water as it occurs and supply it to the subcooler,
Downward face velocity to provide a ice storage how to and sets to be smaller than the floating terminal velocity of the ice nucleation in the bath. At that time, heat the water taken from the heat storage tank.
(Claim 2), for example, water taken from a heat storage tank is cooled by a cooling tower.
Heat exchange with water supplied from the oven (Claim 3), then supercool
Can be supplied to the heat exchanger, and water is taken from the heat storage tank
Finally, it is preferable to take water through an ice nucleus separator (claim 4).
Good.

[0009]

[0010]

[0011]

[0012]

The operation of claim 1 will be described below. First, the terminal velocity of ice nucleation differs depending on the particle size of the ice nucleus, and when calculating the terminal floating velocity, the formula to be determined differs depending on the range of the Reynolds number of each particle, but the ice nucleus is assumed to be spherical. The floating end speed for each particle size obtained as described above is as shown in the table of FIG. This ascending end speed is upward, the water intake section is installed at the bottom of the tank to form a downward surface speed, and if the surface speed is set lower than the ascending end speed, the ice nucleus flows into the water to be taken. Never. Therefore, by appropriately setting the surface speed of the water intake section based on the particle size of the ice nuclei in the sherbet-like ice stored in the heat storage tank, the ice nuclei do not flow into the water to be withdrawn.

According to the second and third aspects, the water taken in is heated once and then supplied to the subcooler, so that the ice nuclei flowing from the water intake can be melted. In this case, although it depends on the capacity of the subcooler, it is desirable to perform heating in a range where the inlet temperature of the subcooler does not rise more than necessary,
In view of this point, when water is withdrawn, for example, by adjusting the surface speed of the water intake section, or by using an ice nucleus separator such as a mesh for water withdrawal, the particle size of the ice nucleus that allows inflow is reduced to some extent. It is desirable to keep things.

According to 請 Motomeko 2 and 3, preparative face velocity of water portion increased to some extent, limit the particle size of the ice nucleus for ice nucleation separated to some extent, small ice nucleation the inflowing melted by heating The particle size distribution of ice nuclei and the amount of ice nuclei in sherbet-like ice stored in the heat storage tank are measured, and the particle size and amount of ice nuclei flowing in at the set surface velocity , It is possible to calculate the optimal heating amount. By doing so, the most efficient ice storage operation can be performed while preventing the subcooler from freezing.

According to the fourth aspect of the present invention, since water is further taken through an ice nucleus separator such as a mesh, by combining the sizes of the meshes, the selection range of the setting of the surface speed is widened, and more efficient ice storage operation is possible. become. For example, when a 10-mesh mesh is used, the size of one mesh is 2.5 / 10 ³ [m], so that the inflow of ice nuclei having a larger particle diameter into the intake portion is prevented by the mesh. Therefore, the surface velocity of the water intake section is set to the final floating velocity of the particle diameter (5.0 / 1).
0 ² [m / s]) or more, ice nuclei having a size larger than the particle size will not be taken.

The surface velocity of the water intake section can be adjusted by controlling a pump or the like for taking water. However, the surface velocity of the water intake section can also be adjusted by appropriately increasing or decreasing the passage area of the ice nucleus separator such as a mesh while keeping the output of the pump constant. it can. For example, if the passage area is reduced, the surface speed of the water intake section increases. Therefore, if water is taken through a mesh as described in claim 4, by appropriately selecting the size and area of the mesh to be used, the size of the ice nucleus to be captured can be set and the surface speed can be set at the same time. Therefore, a high-efficiency ice heat storage method can be realized as the whole system.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 schematically shows the main components and piping required for carrying out the first embodiment. The heat storage tank 1 for storing the heat source water for air conditioning uses a single tank. Of course, a so-called multi-tank type heat storage tank composed of a plurality of communicating small tanks using an underground slab or the like may be used instead.

Above the heat storage tank 1, there is provided a subcooler 2 which uses brine supplied from a separate refrigerator unit as an ice generation heat source. The supercooled water collides with a collision plate 3 serving as a supercooling release means provided on the upper part of the heat storage tank 1 to release the supercooled state, to generate sherbet-like ice, and the heat storage tank 1
And is stored in the heat storage tank 1 in the form of coexistence with water.

As shown in FIG. 2, in the lower part of the heat storage tank 1,
A water intake space 6 surrounded by the ice nuclei separator 4 and the partition wall 5 made of a mesh is formed, and a water intake 8 provided at the tip of the water intake pipe 7 and provided downward is located in the water intake space 6. . Therefore, ice nuclei having a relatively large particle size are prevented from entering the water intake space 6 by the ice nuclei separator 4, and are not taken in from the water intake 8.

This ice nucleus separator 4 is composed of four unit ice nucleus separators 4a, and each unit ice nucleus separator 4a
Has a panel-like form in which a mesh (10 mesh) is provided in a rectangular frame. The unit ice core separation bodies 4a are independently detachable. Accordingly, by replacing the removed unit of ice nuclei 4a with an appropriate blind plate, or by covering the unit of ice nuclei 4a with an appropriate blind lid, the area that can be passed into the intake space 6 can be changed. . By changing the passable area of the ice nuclei separator 4 in this manner, the surface velocity of the water intake 8 can be changed.

Incidentally, the passage area per unit ice nucleus separator 4a used in the present embodiment is 0.81 [m ² ]. Therefore, if all four units are unit ice nucleus separators 4a, the passage area is as follows. Is 3.24 [m ² ]. In this case, for example, the surface velocity at a flow rate of 1600 [l / min] is 0.0082.
[M / s], and if the unit ice nuclei separators 4a are sequentially reduced one by one, the surface velocity at that time is 0.0110 [m
/ S], 0.0165 [m / s], 0.0333 [m / s]
Can be changed.

The intake pipe 7 is provided with a pump 9. Water taken from the heat storage tank 1 through the intake pipe 7 is supplied to the supercooler 2 by the pump 9. Is provided. The heat exchanger 10 is a liquid-liquid type heat exchanger, and performs heat exchange between hot water supplied from a cooling tower (not shown) and the water taken out. Since these cooling towers and refrigerators can be used already installed in a building or the like, it is not necessary to introduce new dedicated equipment. The warm water whose temperature has been reduced by the heat exchange is returned to a refrigerator (not shown). The heat storage tank 1 is controlled by the heat exchanger 10.
The amount of heating for the water taken from is adjusted. In addition, effective use can be achieved by a configuration in which the cooling water is heated by the return water from the secondary side of the cold water, and the cold water whose temperature is lowered is supplied to the heat storage or the secondary side.

The main equipment and piping systems for carrying out the present embodiment are constructed as described above, and in order to evaluate the efficiency of ice storage operation using them, the operation efficiency, supercooling Degree and ice making efficiency were determined as follows. Here, the operating efficiency is represented by the following equation: operating efficiency [%] = 100 [%] − freezing loss rate [%], and the freezing loss rate in the above equation is the freezing loss rate [%] = (Heat storage stop time due to freezing of the subcooler / total heat storage time up to the target IPF) × 100, and the subcooling rate is the subcooling rate [−] = (supercooler inlet / outlet temperature Difference-Subcooler inlet temperature) / Supercooler inlet / outlet temperature difference, and ice making efficiency is an index expressed by ice making efficiency [%] = operating efficiency [%] x subcooling degree [-].

As for the result of the long-time operation, the temperature of the water in the heat storage tank 1 is 0 ° C.
When the surface velocity of the supercooler 2 is 0.005 [m / s], it is heated by the heat exchanger 10 to set the inlet temperature of the subcooler 2 to 0.4 ° C., the operation efficiency, the degree of subcooling, The ice making efficiency was 92.3 [%], 0.8 [-], and 73.8 [%], respectively. Further, the heating amount is increased to lower the inlet temperature of the subcooler 2 to 0.
The operating efficiency, subcooling rate and ice making efficiency at 6 ゜ C are as follows:
100.0 [%], 0.7 [-], 70.08 respectively
[%]. For comparison, the operating efficiency, the degree of subcooling, and the efficiency of ice making when the inlet temperature of the subcooler 2 was set to 0.2 ° C. under the same conditions and the heating amount was reduced were 5%, respectively.
9.2 [%], 0.9 [-] and 53.3 [%]. Therefore, by setting an appropriate heating amount, it is possible to increase efficiency (operation efficiency, ice making efficiency).

When the surface speed is changed while keeping the inlet temperature of the subcooler 2 at the same temperature, the inlet temperature becomes 0.4 ° C.
In each case of 0.6 ° C., it was also confirmed that the smaller the surface speed, the higher the operation efficiency and the ice making efficiency. Therefore,
The ice storage operation can be performed with high efficiency by appropriately adjusting the surface speed and the heating amount based on the particle size distribution and the amount of ice nuclei in the generated sherbet-like ice.

[0026]

According to the first aspect, the surface speed of the water intake section is appropriately set based on the particle size of the ice nucleus in the sherbet-shaped ice stored in the heat storage tank, so that the ice nucleus is added to the water to be withdrawn. Does not flow in. Therefore, it is possible to prevent ice nuclei from flowing into the subcooler and freezing during operation of the subcooler.

According to the second and third aspects, the water taken in is heated once and then supplied to the supercooler, so that the ice nucleus flowing in during the water intake is melted by heating and the supercooler freezes. There is no.

Further, according to claim 2 and 3, the particle size of the ice nucleus flowing during intake by setting the surface speed can be reduced accordingly, the heating amount necessary minimum and correspondingly can do. Therefore, highly efficient ice storage operation is possible.

According to the fourth aspect, since water is taken through the ice nucleus separator such as a mesh, the inflow of the ice nucleus having a relatively large particle size at the time of water taking is prevented regardless of the surface velocity. Therefore, the setting range of the surface speed is widened, and more efficient ice storage operation is possible. The surface velocity can be adjusted at the same time by appropriately increasing or decreasing the passage area of the ice nucleus separator such as a mesh.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of main equipment and a piping system in an embodiment.

FIG. 2 is a perspective view of an ice nucleus separator in an embodiment.

FIG. 3 is a table showing the relationship between the particle size of ice nuclei and the terminal speed of ascent.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heat storage tank 2 supercooler 3 collision plate 4 ice nucleus separator 7 intake pipe 8 intake port 9 pump 10 heat exchanger

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuru Moriya 3-7-25 Sagamigaoka, Zama City, Kanagawa Prefecture Sunlight Hills 203 (72) Inventor Kazunori Eto 4-15-12 Morino, Machida, Tokyo Terada Building Morino B-311 (72) Inventor Tadashi Matsumoto 3-14-50 Tsumadakita, Atsugi-shi, Kanagawa Honatsutsugi A-103 (56) References JP-A-2-166330 (JP, A) JP-A-4-263724 (JP, A) JP-A-4-98095 (JP, A) JP-A-1-169732 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 5/00

Claims (4)

(57) [Claims] 1. A water drawn from a heat storage tank for storing heat source water for air conditioning is supplied to a supercooler installed outside the heat storage tank, and is generated by supercooled water discharged from the supercooler. In the ice heat storage method in which ice / water slurry is supplied into the heat storage tank and ice / water coexists in the heat storage tank , water is collected so as to generate a downward surface velocity in the heat storage tank , and the water is supercooled.
Supplies to却器ice thermal storage how to and sets as its downward face velocity is smaller than the floating terminal velocity of <br/> ice nucleation in the bath. 2. A peroxide was heated to intake water from the thermal storage tank
The ice heat storage method according to claim 1, wherein the ice heat storage is supplied to a cooler . 3. Water supplied from a heat storage tank is supplied from a cooling tower.
2. A heat exchanger for supplying heat to a subcooler after exchanging heat with water.
3. The ice heat storage method according to item 1. 4. The ice storage method according to 請 Motomeko 1, 2 or 3 you intake through ice nucleus separator in again to intake from the heat storage tank.