JP3695888B2 - Cooling system using brine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling system using brine for cooling foods in a plurality of showcases in a supermarket, for example.
[0002]
[Prior art]
Conventionally, as a cooling method of a showcase in a supermarket or the like, a direct expansion type in which a heat exchanger in the showcase is directly cooled using a chlorofluorocarbon refrigerant or the like has been mainstream. There is a problem, and the demand for saving CFCs from the market is increasing. In addition, in order to further prevent food poisoning and the like, there is an increasing demand for high freshness management, such as the introduction of HACCAP management (computer-aided temperature management). As one of responses to such a demand, a cooling system using brine (antifreeze) has been proposed. Examples of the brine (antifreeze) include a mixture of propylene glycol, ethylene glycol, ethanol, or the like and water. An example of using this to cool a plurality of showcases in a supermarket is as follows. A primary circuit consisting of a forward path and a return path is connected to a Blainchler unit, and a secondary circuit is connected to each showcase from the primary circuit. Branch in parallel. Supply of brine to the secondary circuit of each showcase is performed by a pump provided on the primary circuit side, and temperature control of each showcase is performed by ON / OFF control of an electromagnetic valve provided in the showcase. This is done by adjusting the flow rate of the brine flowing to the next circuit.
[0003]
[Problems to be solved by the invention]
However, according to the cooling system using the above-described brine, the flow rate of the brine circulated through the primary circuit by the pump is kept constant, so that depending on the operation status of each showcase (ON / OFF control of the solenoid valve) There has been a problem that the flow rate of the brine in the secondary circuit of the other showcase is greatly changed, and optimal temperature control cannot be performed for each showcase.
[0004]
In addition, since the pump performance and the overall capacity of the Blainchler unit are determined by the number of showcases installed, when adding a showcase, change the pump and Blainchler unit to a high-performance one. There was a problem that it was not possible to add a showcase easily.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling system using brine that can perform optimum temperature control for each showcase without using a substance such as chlorofluorocarbon, and that is easy to add to the showcase. It is in.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, the invention of claim 1 is directed to a cooling system using brine in which a plurality of showcases are cooled using brine, and the outflow from the brachinler unit. A primary circuit in which a primary forward path for flowing brine and a primary return path for flowing brine flowing into the Blinchler unit are configured in a closed circuit, a primary pump for circulating the brine in the primary circuit, A secondary circuit provided in a showcase and having a secondary forward path for taking brine from the primary forward path and flowing it to a heat exchanger and a secondary return path for returning the brine from the heat exchanger to the primary return path, A secondary pump disposed in the secondary forward path for circulating brine in the secondary circuit, and a first electromagnetic wave disposed upstream of the secondary pump in the secondary forward path And a second bypass circuit for circulation that is branched from the secondary return path and connected between the first solenoid valve and the secondary pump in the secondary forward path, and is disposed in the second bypass circuit. And a third electromagnetic valve.
[0007]
According to the present invention, the primary circuit is configured as a closed circuit, and each showcase is appropriately fed with brine from the primary circuit through the secondary circuit, so that the brine flow rate in the primary circuit is stable and each showcase is stable. The brine supply amount to the case side (secondary circuit side) is also less affected by other showcases and is stable. Therefore, the cooling performance of each showcase can be stabilized. Further, when the showcase is added, it is not necessary to change the primary pump and the brachinler unit of the primary circuit, and it is easy to add the additional secondary circuit for the extension.
[0008]
Further, the defrosting operation can be performed by closing the first electromagnetic valve and the second electromagnetic valve and opening the third electromagnetic valve.
[0009]
According to a second aspect of the present invention, in the one according to the first aspect, the brine temporarily stored in the heating container is heated by the heating means during the cooling operation in which the brine is not passed through the second bypass circuit. It is characterized by.
[0010]
According to the present invention, since a predetermined amount of heat necessary before the defrost operation can be stored in the brine in the heating container, the defrost of the showcase can be completed in a short time after the start of the defrost operation. The temperature rise of the product can be prevented. That is, it can cope with high freshness management.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
FIG. 1 shows a schematic configuration of a cooling system using brine according to the present invention. The brine cooling system shown in the figure includes a Blinchler unit 1, a brine primary circuit (main brine circuit) 10 constituting a closed circuit, and a plurality of secondary circuits (sub-brine circuits) 20, 20,. ing. In the figure, two secondary circuits 20 and 20 and two showcases S and S to which these circuits are applied are illustrated.
[0013]
The Blinchler unit 1 includes a refrigeration cycle including a compressor 101, a condenser 102, a decompression device 103, and an evaporator 104, and the primary circuit (main brine circuit) 10 is connected to the evaporator 104. The primary circuit 10 comprises a primary forward path 11 for supplying brine and a primary return path 13 for collecting brine in a closed circuit. A primary pump 15 is connected to the primary forward path 11, and brine is circulated in the primary circuit by the primary pump 15.
[0014]
As shown in FIG. 2, the secondary circuit 20 is connected to the primary outbound path 11 of the primary circuit 10, and the secondary outbound path 21 to the heat exchanger 27 provided in, for example, the cold air passage of the showcase S, And a secondary return path 23 extending from the heat exchanger 27 to the primary return path 13 of the primary circuit 10. A secondary pump 25 for flowing brine to the secondary circuit 20 is disposed on the secondary forward path 21, and a first electromagnetic valve A is disposed on the upstream side of the secondary pump 25. Has been. Furthermore, a first bypass circuit 31 for circulating brine is provided which is branched from the secondary return path 23 and connected between the solenoid valve A and the secondary pump 25 in the secondary forward path 21, and this first bypass circuit A second electromagnetic valve B is disposed in the valve 31. Furthermore, a second bias circuit 33 is disposed in parallel with the first bypass circuit 31 described above, and a defrost heater 35 is disposed upstream of the second bias circuit 33. A third electromagnetic valve C is disposed on the downstream side. The heater 35 includes a brine heating container (hereinafter simply referred to as “heating container”) 35a for storing brine and a heating element 35b for heating the brine stored in the heating container 35a.
[0015]
Next, the operation of the brine cooling system having the above-described configuration will be described with reference to FIG. 3, FIG. 4, FIG. 5, and FIG. Here, FIG. 3 shows the state of the secondary circuit 20 in the normal operation mode, FIG. 4 shows the state of the secondary circuit 20 when the thermo is OFF, and FIG. 5 shows the state of the secondary circuit 20 when defrosted. Show.
[0016]
FIG. 6 is a timing chart showing the relationship between the operation of the solenoid valves A, B and C and the temperature of each part. The cooling operation (thermocycle operation) in FIG. 6 is that the secondary circuit 20 repeats the state of FIG. 3 and the state of FIG. 4, and the defrost operation is the state of the secondary circuit 20 in the state of FIG. The thick lines in FIGS. 3 to 5 indicate the flow of brine.
[0017]
First, the Blainchler unit 1 and the primary pump 15 are started to circulate brine in the primary circuit 10 and the secondary pump 25 is started. It is assumed that the primary pump 15 and the secondary pump 25 once started are continuously operated without being stopped during the operation of the brine cooling system. As described above, this is to improve the durability of the pump by reducing the damage to the pump as much as possible by starting and stopping the pump, in particular, starting at a low temperature.
[0018]
In the normal operation mode shown in FIG. 3, the solenoid valves A, B, and C are opened, closed, and closed, respectively.
Thus, the brine flows from the primary forward path 11 of the primary circuit 10 into the secondary forward path 21 of the secondary circuit 20 and is supplied to the heat exchanger 27 by the secondary pump 25. The brine is cooled, and cool air whose temperature has been reduced in the heat exchanger 27 flows into the showcase S, and cools, for example, food in the showcase S. The brine after the food is cooled is collected in the primary return path 13 of the primary circuit 10 via the secondary return path 23 and returns to the blownler unit 1. In FIG. 6, this normal operation mode is ON of solenoid valve A, OFF of solenoid valves B and C in the cooling operation, and in the case “a” where the interior temperature gradually decreases in terms of the interior temperature of the showcase. Equivalent to.
[0019]
Next, when the thermo shown in FIG. 4 is OFF, the solenoid valves A, B, and C are closed, opened, and closed, respectively. Thus, the brine is not supplied from the primary forward path 11 to the secondary forward path 21, and the secondary pump 25 causes the downstream side of the secondary forward path 21, the heat exchanger 27, the upstream side of the secondary forward path 23, and the first bypass. It is circulated with the circuit 31. At this time, since the brine is not supplied from the primary circuit 10, the temperature in the showcase S rises. When the thermo is OFF, in FIG. 6, the solenoid valve A is turned off, the solenoid valve B is turned on, and the solenoid valve C is turned off in the cooling operation. It corresponds to the part.
[0020]
According to this embodiment, when all the showcases are cooled in the normal operation mode shown in FIG. 3, for example, even if one showcase is switched to the thermo-OFF operation shown in FIG. Since the brine flow rate is stable, the brine supply amount for the showcase side (secondary circuit side) that is cooled in the normal operation mode shown in FIG. 3 has been switched to the thermo-OFF operation shown in FIG. Stable without being affected by the showcase. Therefore, the cooling performance of each showcase can be stabilized.
[0021]
When the above-described normal operation mode and the thermo OFF, that is, the cooling operation shown in FIG. 6, the brine stored in the defrost heating container 35a of the heater 35 is gradually heated by the heating element 35b and maintained at a predetermined temperature. Thus, the amount of heat necessary for defrosting the showcase S is stored.
[0022]
At the time of defrosting shown in FIG. 5, the solenoid valves A, B, and C are closed, closed, and opened, respectively. Thereby, the brine is not supplied from the primary forward path 11 to the secondary forward path as in the above-described thermo-operation. The brine is circulated by a secondary pump in a closed circuit constituted by the downstream side of the secondary forward path 21, the heat exchanger 27, the upstream side of the secondary return path 23, and the second bypass circuit 33.
Then, brine having the amount of heat necessary for defrosting in the heating container 35a is supplied to the heat exchanger 27 of the showcase S, and a short time defrosting operation is performed. For this reason, there is no possibility of raising the internal temperature of the showcase S. In this defrost operation, in FIG. 6, the solenoid valves A and B are turned off and the solenoid valve C is turned on. The brine temperature in the heating container 35a rapidly decreases, while the showcase chamber temperature rises. However, this temperature rise can be minimized as described above, and does not adversely affect foods and the like.
[0023]
As mentioned above, although one Embodiment of the cooling system using the brine which concerns on this invention was described, this invention is not limited to this.
[0024]
For example, the solenoid valve A and the solenoid valve B open and close alternately, and when one is open, the other is closed, and when one is closed, the other is open, without providing them independently, Instead of these, a switching valve such as a four-way valve may be provided. Similarly, a four-way valve can be used in place of the solenoid valve A and the solenoid valve C.
[0025]
【The invention's effect】
As described above, according to the first aspect of the present invention, the primary circuit is configured as a closed circuit, and each showcase appropriately receives brine from the primary circuit through the secondary circuit. The flow rate of brine is stable, and the amount of brine supplied to each showcase side (secondary circuit side) is less affected by other showcases and is stable. Therefore, the cooling performance of each showcase can be stabilized. Further, when the showcase is added, it is not necessary to change the primary pump of the primary circuit and the brachinler unit, and it is easy to add the additional secondary circuit for the extension.
[0026]
Further, the defrosting operation can be performed by closing the first electromagnetic valve and the second electromagnetic valve and opening the third electromagnetic valve.
[0027]
According to the second aspect of the present invention, since the predetermined amount of heat necessary before the defrost operation can be stored in the brine in the heating container, the defrost of the showcase can be completed in a short time after the start of the defrost operation. Further, it is possible to prevent the temperature rise of the items in the showcase. That is, it can cope with high freshness management.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a brine cooling system according to the present invention.
FIG. 2 is a diagram showing a configuration of a secondary circuit.
FIG. 3 is a diagram showing a secondary circuit in a normal operation mode.
FIG. 4 is a diagram showing a secondary circuit when the thermo is off.
FIG. 5 is a diagram showing a secondary circuit at the time of defrosting.
FIG. 6 is a diagram showing the relationship between the operation of the solenoid valve and the temperature of each part.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Brainchler unit 10 Primary circuit 11 Primary outbound path 13 Primary return path 15 Primary pump 20 Secondary circuit 21 Secondary outbound path 23 Secondary return path 25 Secondary pump 27 Heat exchanger 31 1st bypass circuit 33 2nd Bypass circuit 35 Heater 35a Brine heating vessel 35b Heat generator A 1st solenoid valve B 2nd solenoid valve C 3rd solenoid valve S Showcase

Claims (2)

  In a cooling system using brine, in which a plurality of showcases are cooled using brine, a Blainchler unit, a primary forward path through which brine flows out of the Blainchler unit, and a brine flowing into the Blainchler unit A primary circuit in which the primary return path through which the air flows is closed, a primary pump that circulates the brine in the primary circuit, and each showcase is provided with the brine from the primary outbound path to heat A secondary circuit having a secondary forward path for flowing into the exchanger and a secondary return path for returning brine from the heat exchanger to the primary return path, the secondary circuit being disposed in the secondary outbound path, wherein the brine is contained in the secondary circuit A secondary pump to be circulated, a first solenoid valve disposed upstream of the secondary pump in the secondary forward path, and a branch from the secondary return path; And a second bypass circuit for circulation connected between the first solenoid valve and the secondary pump, heating means and a third solenoid valve disposed in the second bypass circuit. A cooling system using brine.   2. The cooling system using brine according to claim 1, wherein the brine temporarily stored in the heating container is heated by the heating unit during the cooling operation in which the brine does not flow through the second bypass circuit. .

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