JP3723368B2 - Showcase cooling system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling system for cooling a plurality of showcases.
[0002]
[Prior art]
In general, a showcase cooling system is known in which a secondary refrigerant cooled by a primary refrigerant is circulated in a closed loop by a main transfer pump to cool a plurality of showcases connected to the closed loop.
[0003]
In this type, the capacity of the main transfer pump of the secondary refrigerant is determined according to the total value of the refrigerant pressure loss of the plurality of showcases.
[0004]
[Problems to be solved by the invention]
However, in the conventional configuration, when a showcase with a large refrigerant pressure loss and a showcase with a small refrigerant pressure loss are connected to the same closed loop, the capacity of the main conveyance pump is determined according to the total value of all the refrigerant pressure losses. There is a problem that the pump becomes larger, the efficiency of the pump deteriorates, and costs increase.
[0005]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a showcase cooling system that eliminates the above-described problems of the prior art, reduces the size of the main transport pump, increases the pump efficiency, and reduces the manufacturing cost.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is a showcase cooling system for cooling a plurality of showcases connected to the closed loop by circulating a secondary refrigerant cooled by the primary refrigerant in a closed loop by a main transport pump. A plurality of showcases having a small refrigerant pressure loss are connected in parallel to the pipelines constituting the same, and a secondary refrigerant intake pipe is connected to the upstream pipeline and / or the downstream pipeline of the plurality of showcases having a small refrigerant pressure loss. A showcase having a large refrigerant pressure loss is connected, and an in-case transfer pump is connected to the secondary refrigerant intake pipe.
[0007]
In the first aspect of the present invention, the showcase having a large refrigerant pressure loss is connected to the closed loop via the secondary refrigerant intake pipe, and the in-case transfer pump is connected to the secondary refrigerant intake pipe. In the showcase having a large pressure loss, the secondary refrigerant is caused to flow using the in-case transfer pump. Therefore, the capacity of the main transfer pump for circulating the secondary refrigerant in the closed loop can be reduced because the capacity can be determined based on a plurality of showcases with low refrigerant pressure loss.
[0008]
The invention according to claim 2 is the invention according to claim 1, wherein a showcase having a low internal temperature is connected to the upstream pipeline, and a showcase having a high internal temperature is connected to the downstream pipeline. It is characterized by.
[0009]
In the invention described in claim 2, since the temperature of the secondary refrigerant in the upstream pipe line is low, a low-temperature showcase is connected, and since the temperature of the secondary refrigerant in the downstream pipe line is high, connect a high-temperature showcase. By doing so, energy can be used efficiently.
[0010]
According to a third aspect of the present invention, in the showcase cooling system for cooling the showcase connected to the closed loop by circulating the secondary refrigerant cooled by the primary refrigerant in the closed loop by the main transport pump, the closed loop is configured. A showcase with a small refrigerant pressure loss and a bypass line are connected in parallel to the pipeline, and a secondary refrigerant intake pipeline is connected to the upstream pipeline and / or the downstream pipeline of the showcase with a small refrigerant pressure loss. A showcase having a large refrigerant pressure loss is connected, and an in-case transfer pump is connected to the secondary refrigerant intake pipe.
[0011]
In the invention described in claim 3, since the showcase having a small refrigerant pressure loss and the bypass pipe are provided in parallel, the flow and temperature of the refrigerant flowing in the closed loop can be adjusted by adjusting the flow of the bypass. .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0013]
In FIG. 1, reference numeral 1 denotes a circuit of a showcase cooling system. The circuit 1 includes a refrigeration apparatus 3, a main pipeline 5, and a main transfer pump 7, and the main pipeline 5 constitutes a closed loop. The refrigerant device 3 includes a refrigeration cycle including a compressor 9, a condenser 11, a decompression device 13, and an evaporator 15. A primary refrigerant such as chlorofluorocarbon is circulated in the refrigeration cycle. This primary refrigerant exchanges heat with the secondary refrigerant circulating in the main pipe line 5 in the evaporator 15, and this secondary refrigerant circulates in the main pipe line 5 as indicated by an arrow by the main transfer pump 7. As the secondary refrigerant, an antifreeze solution composed of propylene glycol, ethylene glycol, or a mixture of ethanol and water called brine is used.
[0014]
Three secondary refrigerant distribution lines 19 are connected in parallel to the main line 5, and a showcase 31 including a cooler 33 having a small refrigerant pressure loss is connected to each secondary refrigerant distribution line 19. ing.
[0015]
In this embodiment, the capacity of the main transfer pump 7 is determined according to the total value of the cooler 33 with a small refrigerant pressure loss.
[0016]
A secondary refrigerant intake pipe 17 is connected to the upstream pipe 5a of the main pipe 5, and the secondary refrigerant intake pipe 17 is provided with a cooler 23 having a large refrigerant pressure loss, and an internal temperature. A low-temperature refrigeration showcase 21 is connected, and a secondary refrigerant intake pipe 17 is connected to the downstream pipe 5b, and a cooler 27 having a large refrigerant pressure loss is connected to the secondary refrigerant intake pipe 17. And a refrigerated showcase 25 having a high internal temperature is connected. And the in-case conveyance pump 29 is provided in the secondary refrigerant | coolant intake pipe line 17 located in the downstream of each showcase 21 and 25. FIG.
[0017]
Next, the operation of this embodiment will be described.
[0018]
When the operation of the compressor 9 of the refrigeration apparatus 3 is started, the primary refrigerant is cooled by the refrigeration cycle, and the evaporator 15 exchanges heat between the primary refrigerant and the secondary refrigerant, thereby cooling the secondary refrigerant. This secondary refrigerant flows out to the upstream line 5 a of the main line 5 by the main transport pump 7, and flows into the cooler 33 having a small refrigerant pressure loss in the showcase 31 through the secondary refrigerant distribution path 19. The cooler 33 cools the interior of the showcase 31 (not shown), and the secondary refrigerant is circulated through the secondary refrigerant distribution channel 19 to the downstream pipeline 5 b of the main pipeline 5.
[0019]
Further, the secondary refrigerant that has flowed out to the upstream pipe line 5 a flows into the cooler 23 of the refrigeration showcase 21 having a large refrigerant pressure loss and a low internal temperature via the secondary refrigerant intake pipe line 17. The cooler 23 cools the interior of the showcase 21 (not shown). After passing through the cooler 23, the secondary refrigerant is sent out to the upstream pipe line 5a by the in-case transport pump 29.
[0020]
Similarly, the secondary refrigerant that has flowed out to the downstream side pipe 5b flows into the cooler 27 of the refrigerated showcase 25 having a large refrigerant pressure loss and a high internal temperature through the secondary refrigerant intake pipe 17. . The cooler 27 cools the interior of the showcase 25 (not shown). After passing through the cooler 25, the secondary refrigerant is sent out to the downstream pipe line 5b by the in-case transport pump 29.
[0021]
In this embodiment, the showcases 21 and 25 having a large refrigerant pressure loss are connected to the closed loop via the secondary refrigerant intake pipe 17, and the in-case transport pump 29 is connected to the secondary refrigerant intake pipe 17. Thus, the secondary refrigerant is caused to flow through the showcases 21 and 25 having a large refrigerant pressure loss using the in-case transfer pump 29.
[0022]
Therefore, the main transfer pump 7 for circulating the secondary refrigerant in the closed loop can determine the capacity with reference to the plurality of showcases 31 having a small refrigerant pressure loss, and thus can be reduced in size.
[0023]
In addition, a relatively low temperature showcase 21 is connected to the upstream pipeline 5a where the temperature of the secondary refrigerant is low, and a relatively high temperature showcase 25 is connected to the downstream pipeline 5b where the temperature of the secondary refrigerant is high. Because it is energy efficient.
[0024]
Further, since the in-case transport pump 29 is connected to the downstream side of the showcases 21 and 25, the secondary refrigerant flowing through the in-case transport pump 29 is heat-exchanged by the coolers 23 and 25, and the temperature rises. Since it is low, there exists an effect that the efficiency of the pump can be improved.
[0025]
Next, another embodiment will be described.
[0026]
In the circuit 51 of the cooling system shown in FIG. 2, a bypass line 53 is provided in parallel with the showcase 31 having a small refrigerant pressure loss, and a flow rate adjusting valve 54 is provided in the bypass line 53.
[0027]
In this embodiment, the flow rate and temperature of the refrigerant flowing in the closed loop can be adjusted by adjusting the flow rate of the refrigerant in the bypass conduit 53 by adjusting the valve opening degree of the flow rate adjustment valve 54.
[0028]
For example, when one of the showcases 31 is in the defrosting operation, it is necessary to reduce the flow rate of the secondary refrigerant flowing into the showcase 31. In this case, as described above, the flow rate of the secondary refrigerant flowing into the showcase 31 can be decreased by increasing the valve opening degree of the flow rate adjusting valve 54 and increasing the flow rate of the refrigerant in the bypass line 53. .
[0029]
【The invention's effect】
In the first aspect of the present invention, the showcase having a large refrigerant pressure loss is connected to the closed loop via the secondary refrigerant intake pipe, and the in-case transfer pump is connected to the secondary refrigerant intake pipe, thereby In the showcase having a large pressure loss, the secondary refrigerant is caused to flow using the in-case transfer pump. Therefore, the capacity of the main transport pump for circulating the secondary refrigerant in the closed loop can be reduced because the capacity can be determined based on a plurality of showcases having a small refrigerant pressure loss.
[0030]
In the second aspect of the invention, since the temperature of the secondary refrigerant in the upstream pipe line is low, a low-temperature showcase is connected, and since the temperature of the secondary refrigerant in the downstream pipe line is high, connect a high-temperature showcase. By doing so, energy can be used efficiently.
[0031]
In the invention according to claim 3, since the showcase having a small refrigerant pressure loss and the bypass pipe are provided in parallel, the flow and temperature of the refrigerant flowing in the closed loop are adjusted by adjusting the flow of the bypass. be able to.
[Brief description of the drawings]
FIG. 1 is a circuit diagram illustrating an embodiment of a cooling system according to the present invention.
FIG. 2 is a circuit diagram showing another embodiment of the cooling system according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit 3 Refrigeration apparatus 5 Main line 7 Main conveyance pump 17 Secondary refrigerant intake line 21, 25, 31 Showcase 23, 27, 33 Cooler 29 In-case conveyance pump 53 Bypass line

Claims (3)

In a showcase cooling system that circulates a secondary refrigerant cooled by a primary refrigerant in a closed loop with a main conveyance pump and cools a plurality of showcases connected to the closed loop,
A plurality of showcases having a small refrigerant pressure loss are connected in parallel to the pipelines forming the closed loop, and a secondary refrigerant intake pipe is connected to the upstream pipeline and / or the downstream pipeline of the plurality of showcases having a small refrigerant pressure loss. A showcase cooling system, wherein a showcase having a large refrigerant pressure loss is connected through a passage, and an in-case transfer pump is connected to the secondary refrigerant intake pipe. The showcase cooling system according to claim 1, wherein a showcase having a low internal temperature is connected to the upstream pipeline, and a showcase having a high internal temperature is connected to the downstream pipeline. In the cooling system of the showcase that cools the showcase connected to the closed loop by circulating the secondary refrigerant cooled by the primary refrigerant in the closed loop by the main transfer pump,
A showcase having a low refrigerant pressure loss and a bypass pipe are connected in parallel to the pipes constituting the closed loop, and a secondary refrigerant is taken into the upstream pipe line and / or the downstream pipe line of the showcase having a low refrigerant pressure loss. A showcase cooling system, wherein a showcase having a large refrigerant pressure loss is connected via a conduit, and an in-case transport pump is connected to the secondary refrigerant intake conduit.

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