JP2010086748A - Cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system effective for shop illumination LED and not causing deterioration of shop environment. <P>SOLUTION: The cooling system includes a compressor 1, a condensator 2, and a brine circuit 9 which combines a cooling unit 5 circulating a natural coolant such as ammonium, a brine circulating pump 6, a cascade condenser 4, a plurality of showcase electromagnetic valves 7, and a heat-absorbing heat exchanger 8 formed as a heat load each other with a circuit on which an expansion valve 3 and the cascade condenser 4 are connected each other and circulates non-freezing liquid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a cooling system having an LED cooling function.

Patent document 1 discloses a store lighting technique using LEDs.
JP 2006-259813 A

LEDs have the problem of reduced luminous intensity and lifetime due to self-heating, and it is necessary to provide effective cooling means. Moreover, it is customary that the cooling means does not cause deterioration of the in-store environment.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling system that is effective for the store lighting LED and does not cause deterioration of the store environment.

In order to solve the above problems, the present invention includes a cooling device, a brine circuit that circulates brine cooled by the cooling device to a heat load, and an LED attached to a jacket formed by a part of the brine circuit. A cooling system is provided.
As a cooling means for the LED, it is conceivable that a refrigerant of an air conditioner or a refrigerated showcase provided in the store is caused to flow through a jacket to which the LED is attached. However, conventional air conditioners and refrigerated showcases generally use hydrocarbon refrigerants, and the refrigerant downstream from the evaporator is generally a gas with a small specific heat and a low heat transfer rate from the jacket peripheral wall, so the heat of the LED is low. There is a possibility that the LED is hardly cooled to the refrigerant and is not effectively cooled. In the unlikely event that the refrigerant leaks from the jacket, the environment of the store space may be deteriorated. The inventor of the present application uses a cooling system that uses an antifreeze (brine), typically a mixture of propylene glycol, ethylene glycol, ethanol, etc., and water as a refrigerant. Focusing on the fact that it is attracting attention from the viewpoint and is likely to be generalized in the future, the idea was to use a part of the cooling brine circuit as a cooling jacket for the LED. Since the brine is a liquid and generally has a large specific heat and a high heat transfer rate from the jacket peripheral wall as compared with the vaporized hydrocarbon-based refrigerant, the LED can be effectively cooled. Moreover, even if it leaks from a jacket, it is hard to cause deterioration of the in-store environment as compared with hydrocarbon refrigerants.

In a preferred embodiment of the present invention, a part of the brine circuit forming the jacket is disposed downstream of the heat load.
If a part of the brine circuit forming the jacket is disposed downstream of the heat load, the heat load cooling function, which is the original function of the brine circuit, is not impaired.

In a preferred embodiment of the present invention, a plurality of jackets are arranged in parallel.
When a plurality of jackets are arranged in series, the temperature of the brine flowing through the downstream jacket increases, the temperature of the LED attached to the downstream jacket increases, and the luminous intensity decreases. On the other hand, if a plurality of jackets are connected in parallel, there will be no variation in brine temperature for each jacket, and there will be no variation in LED luminous intensity for each jacket.

In a preferred embodiment of the invention, the brine flow in the jacket is a downward flow.
If the flow of the brine in the jacket is a downward flow, the load of the brine circulation pump is reduced, so that the size of the pump can be reduced.

In a preferred embodiment of the present invention, a part forming the jacket of the brine circuit is connected in series with the heat load, the cooling system further includes a bypass flow path bypassing the part forming the jacket of the brine circuit, and the brine circuit And a means for variably controlling the flow rate of the brine flowing into the part forming the jacket.
The need for store lighting is low during the day and high at night. Therefore, the luminous intensity of the LED may be low during the day and high at night. A part forming the jacket of the brine circuit is connected in series with the heat load, a bypass flow path bypassing the part forming the jacket of the brine circuit is disposed, and the brine to the part forming the jacket of the brine circuit If the flow rate of the LED is variably controlled and the flow rate is reduced during the day and the flow rate is increased during the night, the LED cooling effect decreases during the day and increases during the night. Without variably controlling, the luminous intensity of the LED can be low during the day and high during the night. Moreover, since the flow rate of the brine contributing to the cooling of the LED decreases during the day, the load on the brine cooling device is reduced. Also. During the day, the flow rate of the brine flowing through the part forming the jacket of the brine circuit is reduced and the pressure loss of the entire brine circuit is reduced, so that the load of the brine circulation pump is also reduced.

In a preferred aspect of the present invention, the cooling system includes means for variably controlling the power supply to the LEDs.
The power supply to the LED is variably controlled to reduce the power supply during the day and increase the power supply at night. In synchronism with this, the brine supply to the jacket is made small or zero during the day, and the brine supply to the jacket is made large at night. Since the power supply is small during the day, the luminous intensity of the LED decreases, and at night the power supply is large, so the luminous intensity of the LED increases. During the day, the heat generation of the LED is small, so even if the brine supply to the jacket is small, the LED is sufficiently cooled. Even if the brine supply to the jacket is zero, the LED is cooled to ten parts by air cooling. As a result, the durability of the LED is improved. At night, the heat generation of the LED is large, but the supply of brine to the jacket is large so that the LED is sufficiently cooled.

According to the present invention, there is provided a cooling system that is effective for the store lighting LED and does not cause deterioration of the store environment.

A cooling system according to a first embodiment of the present invention will be described.
As shown in FIG. 1, the cooling system A is a cooling system in which a natural refrigerant such as ammonia or CO 2 is circulated in a circuit in which a compressor 1, a condenser 2, an expansion valve 3, and a cascade condenser 4 are interconnected. The apparatus 5, the brine circulation pump 6, the cascade condenser 4, the plurality of refrigerated showcase solenoid valves 7, and the endothermic heat exchanger 8 that forms a heat load are connected to each other, and propylene glycol, ethylene glycol, ethanol And a brine circuit 9 for circulating an antifreeze liquid (brine), which is typically a mixture of water and the like.
A part of the brine circuit 9 forms a jacket 10, and a plurality of store lighting LEDs 11 are attached to the outer surface of the jacket 10. A part of the brine circuit 9 forming the jacket is disposed downstream of the heat absorption heat exchanger 8 with respect to the flow of the brine in the brine circuit 9, and is connected in series to the heat absorption heat exchanger 8.
The flow of brine in the jacket 10 forms a downward flow.
The cooling device 5 is disposed outside the store, and the electromagnetic valve 7, the heat-absorbing heat exchanger 8, the jacket 10, and the LED 11 of the brine circuit 9 are disposed in the store.

In the cooling system A, heat is exchanged between the natural refrigerant flowing through the cascade condenser 4 of the cooling device 5 and the brine to cool the brine. The brine cooled by the cooling device 5 exchanges heat with the air in the refrigerated showcase by the endothermic heat exchanger 8 of the refrigerated showcase to cool the air, thereby cooling the food in the refrigerated showcase.
The brine that has passed through the heat absorption heat exchanger 8 passes through a jacket 10 formed by a part of the brine circuit 9, cools the LED attached to the jacket 10, and then returns to the cascade condenser 4 of the cooling device 5.
By cooling the LED 11, the light intensity and the life of the LED are prevented from decreasing.
Since the brine is a liquid and generally has a large specific heat and a high heat transfer rate from the jacket 10, the LED can be effectively cooled. In addition, even if brine leaks from the jacket 10, the in-store environment is unlikely to deteriorate compared to the hydrocarbon refrigerant.
A part of the brine circuit 9 forming the jacket 10 is arranged downstream of the heat-absorbing heat exchanger 8 of the refrigerated showcase, which is a thermal load, with respect to the flow of the brine. The product in the refrigerated showcase is not affected by the brine heated by the heat of the LED without impairing the heat load cooling function that is the original function of the circuit 9.
Since the brine flow in the jacket 10 is a downward flow, the load of the brine circulation pump 6 is reduced. As a result, the brine circulation pump 6 can be downsized.

A cooling system according to a second embodiment of the present invention will be described.
As shown in FIG. 2, the cooling system B is a cooling system in which a natural refrigerant such as ammonia or CO 2 is circulated in a circuit in which a compressor 21, a condenser 22, an expansion valve 23, and a cascade condenser 24 are interconnected. A device 25, a brine circulation pump 26, a cascade condenser 24, a solenoid valve 27, and a heat exchanger 28 for heat absorption of an air conditioner that forms a heat load are connected to each other, and propylene glycol, ethylene glycol, ethanol, etc. and water And a brine circuit 29 for circulating an antifreeze liquid (brine) as a representative example.
A part of the brine circuit 29 forms a jacket 30, and a plurality of store lighting LEDs 31 are attached to the outer surface of the jacket 30. A part of the brine circuit 29 forming the jacket is disposed downstream of the endothermic heat exchanger 28 with respect to the brine flow in the brine circuit 29 and is connected in series to the endothermic heat exchanger 28.
The flow of brine in the jacket 30 forms a downward flow.
The cooling device 25 is disposed outside the store, and the electromagnetic valve 27, the heat-absorbing heat exchanger 28, the jacket 30, and the LED 31 of the brine circuit 29 are disposed within the store.
Also in the cooling system B, the same effect as the cooling system A is obtained.

In the cooling systems A and B, when a plurality of jackets 10 and 30 are disposed, it is desirable that the plurality of jackets 10 and 30 be disposed in parallel as shown by a one-dot chain line in FIGS. When a plurality of jackets 10 and 30 are connected in series, the temperature of the brine flowing through the downstream jacket increases, the temperature of the LEDs 11 and 31 attached to the downstream jacket increases, and the luminous intensity decreases. On the other hand, if a plurality of jackets 10 and 30 are connected in parallel, there will be no variation in the brine temperature for each jacket, and there will be no variation in the brightness of the LEDs 11 and 31 for each jacket.

As shown in FIGS. 3 (a) to 3 (d), bypass channels 9 ′ and 29 ′ that bypass the part forming the jackets 10 and 30 of the brine circuits 9 and 29 are disposed, and the brine circuits 9 and 29 are disposed. Means for variably controlling the flow rate of the brine flowing into the part forming the jackets 10 and 30 of the circuit, that is, branching between the part forming the jackets 10 and 30 of the brine circuits 9 and 29 and the bypass flow paths 9 ′ and 29 ′ On-off valves 43 and 44 attached to the three-way valves 41 and 42 attached to the points, a part forming the jackets 10 and 30 of the brine circuits 9 and 29 and the bypass passages 9 ′ and 29 ′, and the brine circuit 9 , 29 may be provided with a flow rate adjusting valve 45 attached to a part of the jackets 10 and 30.
The need for store lighting is low during the day and high at night. Accordingly, the luminous intensity of the LEDs 11 and 31 may be low during the day and high at night. Three-way valves 41 and 42, on-off valves 43 and 44, and flow rate adjusting valve 45 are used to variably control the flow rate of brine flowing into a part of the jackets 10 and 30 of the brine circuits 9 and 29. If the flow rate is reduced and the flow rate is increased at night, the cooling effect of the LEDs 11 and 31 decreases during the day and increases during the night, so that the LED 11, 31 can be controlled without variably controlling the power supply to the LEDs 11, 31. The intensity of 31 can be low during the day and high during the night. Moreover, since the flow rate of the brine contributing to the cooling of the LEDs 11 and 31 decreases during the day, the load on the cooling device 5 is reduced. Also. During the day, the flow rate of the brine flowing through a part forming the jacket of the brine circuits 9 and 29 decreases, and the flow rate of the brine flowing through the bypass passages 9 ′ and 29 ′ shorter than the part increases. The pressure loss of the entire circuit is reduced, and the load on the brine circulation pump 6 is reduced.

In addition to the configuration of FIG. 3, an inverter control device that variably controls power supply to the LEDs 11 and 31 and a variable resistor may be provided.
The power supply to the LEDs 11 and 31 is variably controlled to reduce the power supply during the day and increase the power supply at night. In synchronization with this, the brine supply to the jackets 10 and 30 is made small or zero during the day, and the brine supply to the jackets 10 and 30 is made large at night. Since the power supply is small during the daytime, the light intensity of the LEDs 11 and 31 decreases, and since the power supply is large at night time, the light intensity of the LEDs 11 and 31 increases. Since the heat generation of the LEDs 11 and 31 is small during the day, the LEDs 11 and 31 are sufficiently cooled even if the brine supply to the jackets 10 and 30 is small. Even if the brine supply to the jackets 10 and 30 is zero, the LEDs 11 and 31 are cooled to ten parts by air cooling. As a result, the durability of the LEDs 11 and 31 is improved, and the loads on the cooling device 5 and the brine circulation pump 6 during the day are reduced. At night, the LEDs 11, 31 generate a large amount of heat, but since the brine supply to the jackets 10, 30 is large, the LEDs 11, 31 are sufficiently cooled.

The LEDs 11 and 31 may illuminate the inside of the store, illuminate the outside of the store, or illuminate the inside of the refrigerated showcase.
The shape of the jackets 10 and 30 is not particularly limited. Any device may be used as long as it can form the brine flow path and can attach the LEDs 11 and 31 to the outer surface.
The jackets 10 and 30 may be placed horizontally or vertically. A plurality of jacket assemblies composed of a plurality of jackets connected in series may be connected in parallel. When there is a single jacket, or when a plurality of single jackets are arranged in parallel, a jacket assembly comprising a plurality of jackets connected in series with the outlet disposed below the inlet of the jacket. In the case of disposing a solid body, it is desirable from the viewpoint of reducing the load of the brine circulation pump 6 to dispose the outlet below the inlet of the jacket assembly so that the brine flow in the jacket is a downward flow.

It is a block diagram of the cooling system which concerns on 1st Example of this invention. It is a block diagram of the cooling system which concerns on 2nd Example of this invention. It is a partial block diagram of the cooling system which concerns on the other Example of this invention.

Explanation of symbols

A, B Cooling system 1, 21 Compressor 2, 22 Condenser 3, 23 Expansion valve 4, 24 Evaporator 5, 25 Cooling device 6, 26 Brine circulation pump 7, 27 Solenoid valve 8, 28 Endothermic heat exchanger 9 , 29 Brine circuit 9 ', 29' Bypass channel 10, 30 Jacket 11, 31 LED
41, 42 3-way valve 43, 44 On-off valve 45 Flow rate adjustment valve

Claims (6)

A cooling system comprising: a cooling device; a brine circuit for circulating brine cooled by the cooling device to a heat load; and an LED attached to a jacket formed by a part of the brine circuit. The cooling system according to claim 1, wherein the portion forming the jacket of the brine circuit is disposed downstream of the heat load. The cooling system according to claim 1 or 2, wherein a plurality of jackets are arranged in parallel. The cooling system according to any one of claims 1 to 3, wherein a flow of brine in the jacket is a downward flow. A part forming the jacket of the brine circuit is connected in series with the heat load, bypassing the part forming the jacket of the brine circuit, and a flow rate of the brine flowing into the part forming the jacket of the brine circuit The cooling system according to any one of claims 1 to 4, further comprising: means for variably controlling the temperature. 6. The cooling system according to claim 5, further comprising means for variably controlling power supply to the LED.

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