JP4427971B2 - Ice heat storage method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ice heat storage method and an ice heat storage device provided in an air conditioner or the like.
[0002]
[Prior art]
As a system for building or district cooling, there is a cooling system that makes ice using low-cost nighttime electricity and stores heat, and in the daytime cooling, there is a cooling system that cools by releasing the stored heat by melting ice, such cooling system is It has an ice heat storage device.
[0003]
A conventional ice heat storage device will be described with reference to FIG.
[0004]
In FIG. 2, 1 is a cooling tower, 2 is a turbo refrigerator, 3 is an ice storage tank, 4 is a first heat exchanger, 5 is a second heat exchanger, 6 is a third heat exchanger, and 10 is a turbo refrigerator. The heat exchanger is shown.
[0005]
A first circulation line 7 communicating with the bottom of the ice heat storage tank 3 is connected to the heat exchanger 10, and a first circulation pump 8 and a first valve 9 are provided in the middle of the first circulation line 7. A second circulation line 11 connected from the turbo chiller 2 to the ice heat storage tank 3 is provided, and the second circulation line 11 includes a second circulation pump 12, a second valve 13, and the like from the turbo chiller 2 side. A supercooling releaser 14 is provided.
[0006]
A third circulation line 15 branched from between the first circulation pump 8 and the first valve 9 of the first circulation line 7 is connected to the ice heat storage tank 3 via the second heat exchanger 5, A third valve 16 is provided on the upstream side of the second heat exchanger 5 in the third circulation line 15.
[0007]
A branch line 17 that passes through the third heat exchanger 6 is provided downstream of the first circulation pump 8 in the first circulation line 7, and a branch circulation pump 18 is provided in the branch line 17.
[0008]
A fourth circulation line 19 connected to the upstream side of the turbo chiller 2 in the second circulation line 11 and the downstream side of the second circulation pump 12 in the second circulation line 11 and passing through the first heat exchanger 4. A fourth valve 21 is provided on the upstream side of the first heat exchanger 4 in the fourth circulation line 19.
[0009]
A first load line 22 is connected to the first heat exchanger 4, a second load line 23 is connected to the second heat exchanger 5, and the second load line 23 and the first load line 22 are connected to a cooling device ( (Not shown) or the like. A third load line 24 is connected to the third heat exchanger 6, and the third load line 24 is connected to a preheating source (not shown).
[0010]
The cooling tower 1 and the turbo refrigerator 2 are connected by a cooling line 25. The cooling line 25 is provided with a cooling circulation pump 26, and the turbo refrigerator 2 is in a state where the turbo refrigerator 2 is in operation. Cooling waste heat from.
[0011]
When heat storage is performed in the ice heat storage device, the turbo refrigerator 2 is driven, and the refrigerant (water) is circulated through the second circulation line 11.
[0012]
With the third valve 16 and the fourth valve 21 closed and the first valve 9 and the second valve 13 opened, the first circulation pump 8, the branch circulation pump 18, and the second circulation The pump 12 is driven, and cold water is pumped from the ice heat storage tank 3 and sent to the heat exchanger 10. The branch circulation pump 18 circulates a part of the pumped cold water to the third heat exchanger 6 and is heated by the third heat exchanger 6, and the cold water supplied to the heat exchanger 10 is circulating. Set the temperature so that it does not freeze. The chilled water is cooled to a supercooled state by the heat exchanger 10, and the supercooled water is made into ice water by the supercool release unit 14, and the ice water is returned to the ice heat storage tank 3.
[0013]
Water in the ice heat storage tank 3 is gradually made into ice by circulating the first circulation line 7 and the second circulation line 11 of the refrigerant and driving the turbo chiller 2 to store heat.
[0014]
When cooling is performed, the first valve 9 is closed, the third valve 16 is opened, and the first circulation pump 8 is driven.
[0015]
The cold water pumped up from the ice heat storage tank 3 dissipates heat in the second heat exchanger 5, cools the refrigerant on the heat load side circulating through the second load line 23, raises the temperature, and the ice heat storage tank Returned to 3.
[0016]
When the heat load is large and the cooling by the second heat exchanger 5 is not sufficient, the cooling by the turbo refrigerator 2 is performed in addition to the cooling by the second heat exchanger 5.
[0017]
The second valve 13 is closed, the fourth valve 21 is opened, and the turbo refrigerator 2 and the second circulation pump 12 are driven. The cold water cooled by the turbo refrigerator 2 circulates in the fourth circulation line 19, and the first heat exchanger 4 cools the refrigerant circulating in the first load line 22.
[0018]
In addition to the above conventional example, an ice heat storage device is disclosed in Patent Document 1, for example.
[0019]
[Patent Document 1]
JP-A-5-118588 [0020]
[Problems to be solved by the invention]
In the conventional ice heat storage device, in the circulation line for making ice, a part of the cold water circulated by the third heat exchanger 6 up to a predetermined temperature is used so that the cold water does not freeze during the circulation. Heated by an external heat source. For this reason, there is a problem that the coefficient of performance of the ice heat storage device decreases, and in addition to the first heat exchanger 4 and the second heat exchanger 5 that cool the refrigerant of a heat load device such as a cooling device (not shown). In addition, since the third heat exchanger 6 for heating the cold water is provided, there is a problem that the installation of the heat exchanger and the configuration of the piping and the like are complicated.
[0021]
In view of such circumstances, the present invention aims to improve the coefficient of performance in an ice heat storage device and to simplify the configuration of the ice heat storage device.
[0022]
[Means for Solving the Problems]
The present invention comprises an ice heat storage tank, a first heat exchanger, a turbo refrigerator, and a first circulation pump, a circulation line for circulating the refrigerant of the ice heat storage tank, a second heat exchanger, and a second circulation pump. And the other circulation line for circulating the refrigerant of the ice heat storage tank, and heating the refrigerant by the first heat exchanger, and disconnecting the other circulation line at the time of the ice heat storage, the turbo refrigerator An ice heat storage method for cooling the refrigerant and making ice, and a circulation line comprising an ice heat storage tank, a first heat exchanger, a turbo refrigerator, and a first circulation pump for circulating the refrigerant in the ice heat storage tank; An ice heat storage method comprising a second heat exchanger and a second circulation pump, and having another circulation line for circulating the refrigerant of the ice heat storage tank, and operating the other circulation line during cooling, During cooling, the turbo chiller and the first heat exchanger are installed as the load increases. No closed circulation line is constituted, it relates to ice thermal storage method of operating the closed circulation line.
[0023]
The present invention also includes an ice heat storage tank, a first heat exchanger, a turbo refrigerator, and a first circulation pump, a circulation line for circulating the refrigerant of the ice heat storage tank, a second heat exchanger, and a second circulation. An ice heat storage device comprising a pump and another circulation line for circulating the refrigerant of the ice heat storage tank, wherein the first heat exchanger and the second heat exchanger are capable of exchanging heat with a heat load side. Furthermore, the present invention relates to an ice heat storage device in which a closed circulation line including the turbo chiller and the first heat exchanger is configured in response to an increase in load.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0025]
FIG. 1 shows a schematic configuration of an ice heat storage device according to the present invention. In FIG. 1, the same components as those shown in FIG.
[0026]
The first circulation line 28 connected to the ice heat storage tank 3 is connected to the turbo chiller 2 via the first heat exchanger 4, and the first circulation line 28 is connected to the first heat exchanger 4 upstream of the first heat exchanger 4. A valve 29 and a first circulation pump 31 are provided. Further, a bypass pipe 32 is provided for connecting the inlet side and the outlet side of the first heat exchanger 4 of the first circulation line 28, and a bypass valve 33 is provided in the bypass pipe 32.
[0027]
A second circulation line 34 is provided to connect the ice heat storage tank 3 from the turbo chiller 2, and the supercooling release unit 14 is provided in the second circulation line 34.
[0028]
The third circulation line 36 connected to the ice heat storage tank 3 is connected to the ice heat storage tank 3 via the second heat exchanger 5, and upstream of the second heat exchanger 5 in the third circulation line 36. Are provided with a second valve 37 and a second circulation pump 38.
[0029]
The downstream side of the first valve 29 and the second circulation line 34 are connected by the bypass circulation line 39 in the water of the ice storage tank 3, and a fourth valve 41 is provided in the bypass circulation line 39.
[0030]
In FIG. 1, reference numeral 42 denotes a heat load such as a cooling device, and a first load line 43 is formed between the first heat exchanger 4 and the heat load 42, and the first load circulation pump is connected to the first load line 43. 44 is provided. A second load line 45 is formed between the heat load 42 and the second heat exchanger 5, and a second load circulation pump 46 is provided in the second load line 45. Part of the first load line 43 and the second load line 45 is shared, and the first load line 43 and the second load line 45 are branched by the collective distribution pipe 47 and the collective distribution pipe 48. Has been.
[0031]
First, the ice heat storage operation will be described.
[0032]
The second valve 37, the bypass valve 33, and the fourth valve 41 are closed, the first valve 29 is opened, the first circulation pump 31 is driven, and the turbo refrigerator 2 is driven. Further, the first load circulation pump 44 is driven at a low speed to circulate a small flow rate of refrigerant through the first load line 43. The circulation amount is set in advance with a lower limit flow rate so that the minimum flow rate does not fall below the lower limit flow rate. Note that the heat load 42 is stopped during the ice heat storage operation.
[0033]
The fluid temperature on the outlet side of the first heat exchanger 4 is detected by a temperature detector (not shown), and the cold water pumped from the ice heat storage tank 3 is cooled to a predetermined temperature by the first heat exchanger 4. For example, cold water is heated to a temperature of 0.2 ° C. to 0.5 ° C. at which it does not freeze. The turbo refrigerator 2 supercools the cold water, and the supercooled water that has been supercooled is made into ice by the supercool releaser 14 and returned to the ice heat storage tank 3 as ice water. Ice is gradually stored in the process of cold water circulating through the first circulation line 28 and the second circulation line 34.
[0034]
Note that the heating amount in the first heat exchanger 4 may be small, and the bypass valve 33 may be opened so that a part of the cold water is heated in the first heat exchanger 4.
[0035]
Next, when cooling is performed, the second valve 37 is opened and the second circulation pump 38 is driven with the turbo refrigerator 2 stopped. The cold water pumped by the second circulation pump 38 passes through the second heat exchanger 5 and is returned to the ice heat storage tank 3.
[0036]
When the second load circulation pump 46 is driven, the refrigerant in the second load line 45 circulates between the heat load 42 and the second heat exchanger 5 and is cooled by cold water in the second heat exchanger 5. Further, heat is dissipated by the heat load 42 and cooling is performed.
[0037]
When the heat load at the heat load 42 is large and it is not possible to cope with the cooling only by the second heat exchanger 5, the cooling by the turbo refrigerator 2 is added.
[0038]
That is, the first valve 29 and the bypass valve 33 are closed, and the fourth valve 41 is opened. In this state, a closed circulation line including the turbo refrigerator 2 and the first heat exchanger 4 is formed by the second circulation line 34 and the bypass circulation line 39.
[0039]
The first circulation pump 31 is driven, the refrigerant (water) is circulated between the first heat exchanger 4 and the turbo chiller 2, the refrigerant is cooled, and circulates through the first load line 43 by the refrigerant. The refrigerant to be cooled is cooled, and the cooling by the turbo refrigerator 2 is added.
[0040]
The fluid temperature on the outlet side of the first heat exchanger 4 is detected by a temperature detector (not shown), and the temperature of the cold water is 5.0 ° C. to 9.0 ° C. 4 is controlled. The amount of heat exchange is controlled by adjusting the opening of the fourth valve 41, adjusting the amount of chilled water circulating in the first circulation pump 31, and the like.
[0041]
In the ice heat storage device according to the present invention described above, the heating heat source of the cold water in the ice heat storage operation is the heat load 42, and the heat source in the same system is used, so that the coefficient of performance is improved.
[0042]
Furthermore, since the first heat exchanger 4 for cooling is used as the heat exchanger for cooling water, it is not necessary to provide a separate heat exchanger for cooling water, and the number of heat exchangers may be small. The piping structure is also simplified.
[0043]
【The invention's effect】
As described above, according to the present invention, the ice heat storage tank, the first heat exchanger, the turbo refrigerator, and the first circulation pump, the circulation line for circulating the refrigerant of the ice heat storage tank, and the second heat exchange are provided. And a second circulation pump that circulates the refrigerant in the ice heat storage tank and heats the refrigerant with the first heat exchanger, and stores the other circulation line at the time of ice heat storage. When the ice is made in the circulation line, the coefficient of performance is improved, and the first heat exchanger for cooling can heat the cold water during ice making. It can also be used as a heat exchanger, and exhibits excellent effects such as simplification of the configuration of the ice heat storage device.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.
FIG. 2 is a schematic configuration diagram illustrating a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cooling tower 2 Turbo refrigerator 3 Ice heat storage tank 4 1st heat exchanger 5 2nd heat exchanger 14 Supercooling release device 28 1st circulation line 29 1st valve 31 1st circulation pump 32 Bypass pipe 33 Bypass valve 34 1st 2 circulation line 36 3rd circulation line 37 2nd valve 38 2nd circulation pump 39 Bypass circulation line 41 4th valve 42 Thermal load 43 1st load line 45 2nd load line

Claims (1)

One circulation line comprising an ice heat storage tank, a first heat exchanger, a turbo refrigerator, and a first circulation pump for circulating the refrigerant of the ice heat storage tank, a second heat exchanger and a second circulation pump provided to have the other side of the circulation line for circulating refrigerant in the ice thermal storage tank, the one circulation line is the thermal load is cooled through the first heat exchanger, the other side of the circulation line is the the thermal load is cooled through the second heat exchanger, at the time of the ice cold storage while heating the refrigerant in the other hand the first heat exchanger disconnect circulation line from the one circulation line, the turbo chiller in the refrigerant cooled by ice, during cooling by operating the circulation line of the other side disconnect said one circulation line from the other circulation line, the heat load is cooled through the second heat exchanger, bypass circulation line with an increase of the thermal load of the cooling The connection with the downstream side of the turbo chiller and upstream of the first circulating pump, a closed circulation line for circulating refrigerant from the one of the circulation line disconnect the ice heat storage tank is constructed, the first heat by ice thermal storage method characterized by cooling the heat load exchanger and through the second heat exchanger by the other side of the circulation line and the closed circulation line.

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