JP3813384B2 - Brine showcase - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brine showcase for heat exchange in a liquid, ie brine.
[0002]
[Prior art]
Conventionally, as this type of showcase, Japanese Patent Laid-Open No. 10-274463 (F25D17 / 02) discloses a cooling system using brine in which a plurality of showcases are cooled using brine, A primary circuit in which a primary forward path for flowing brine flowing out of the Blainchler unit and a primary return path for flowing brine flowing into the Blainchler unit are configured as a closed circuit, and the brine is circulated in the primary circuit. A primary pump, a secondary forward path that is provided in each showcase and takes in brine from the primary forward path and flows to the heat exchanger, and a secondary return path that returns the brine from the heat exchanger to the primary return path A cooling system using brine with a secondary circuit is disclosed.
[0003]
And as a brine of this cooling system, the antifreeze which mixed propylene glycol, ethylene glycol, ethanol, etc. and water is used.
[0004]
[Problems to be solved by the invention]
In the related art as described above, when the showcase is cooled because of the use of the antifreeze liquid, it is necessary to always cool the brine by the Blainchler unit.
[0005]
For this reason, there is a risk that the showcase will be insufficiently cooled when it is difficult for the Blinchler unit to exhibit the desired cooling capacity, such as when the outside air temperature is high.
[0006]
The present invention has been made in view of the above-described problems, and provides a brine showcase aimed at preventing a cooling capacity shortage as much as possible.
[0007]
[Means for Solving the Problems]
As means for achieving the above object, according to claim 1 of the present invention, the showcase is cooled using a liquid, and the liquid is cooled by a refrigerator and frozen to be liquid. A slurry brine generation tank that solidifies a part of the slurry brine, a transport pump that circulates the liquid cooled in the slurry brine generation tank to the heat exchanger of the showcase, and an upper liquid in the slurry brine generation tank. A brine supply pipe for supplying to the heat exchanger, and a lower brine supply pipe for supplying the lower liquid in the slurry brine generation tank to the heat exchanger, the slurry brine generation tank and the heat exchanger A temperature sensor is provided in between, and when the temperature detected by the temperature sensor is equal to or higher than a predetermined temperature, a brine showcase for supplying liquid from the lower brine supply pipe to the heat exchanger is provided.
[0008]
In this way, in the slurry brine generation tank, a part of the liquid is solidified by lowering the temperature of the liquid, and the liquid cooled by the solid latent heat of melting is circulated and supplied to the heat exchanger.
[0009]
Further, in the slurry brine generation tank, when there is a solid, the liquid located in the upper part is at a low temperature and the liquid located in the lower part is at a high temperature.
[0010]
Furthermore, normally, at the time of cooling, the liquid located in the upper part in the slurry brine generation tank is sent to the heat exchanger, but when the solid in the slurry brine generation tank has completely melted, it is located in the lower part in the slurry brine generation tank. Since the temperature of the liquid is lower, the temperature of the liquid flowing into the heat exchanger is detected by the temperature sensor. If the temperature is equal to or higher than the predetermined temperature, the liquid is supplied from the lower brine supply pipe to the heat exchanger.
[0011]
In the invention of claim 2, a plurality of transfer pumps are provided, a temperature sensor is provided between the slurry brine generation tank and the heat exchanger, and when the detected temperature of the temperature sensor is equal to or higher than a predetermined temperature, a plurality of transfer pumps are provided. The brine showcase according to claim 1, wherein the carrier pump is operated.
[0012]
As described above, when the temperature of the liquid flowing into the heat exchanger becomes equal to or higher than a predetermined temperature, a plurality of transport pumps are operated to increase the flow rate in order to prevent the cooling capacity from being insufficient.
[0013]
According to a third aspect of the present invention, there is provided the brine showcase according to the second aspect, wherein the liquid is supplied from the lower brine supply pipe to the heat exchanger immediately before the defrost of the heat exchanger.
[0014]
Thus, immediately before defrosting, the higher temperature liquid in the brine generation tank, that is, the lower liquid is supplied from the lower brine supply pipe to the heat exchanger and preheated.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a cooling circuit of the present invention, FIG. 2 is an operation diagram of a pump and a solenoid valve according to the presence or absence of ice, FIG. 3 is an operation diagram of the pump and the solenoid valve at the time of defrosting, and FIG. FIG. 5 is a relationship diagram of the ice making rate of brine and the brine temperature.
[0017]
1 is a slurry brine generation tank 1 for storing a liquid (brine), for example, water, etc., in the slurry brine generation tank 1, together with a compressor and a condenser (not shown) provided in the refrigerator 2. An evaporator 3 forming a refrigeration cycle is provided. The evaporator 3 is located above the brine in the slurry brine generation tank 1.
[0018]
In the cooling circuit of the present invention, the above-described slurry brine generation tank 1, a plurality of showcase heat exchangers 4, 4, 4,... Connected at. These heat exchangers 4, 4, 4,... And brine transfer pumps 5A, 5B are connected in parallel.
[0019]
The slurry brine generation tank 1 is provided with an upper brine supply pipe 7 and a lower brine supply pipe 8 at the upper and lower parts, and the brine supply pipes 7 and 8 are provided with electromagnetic valves 9A and 9B. ing.
[0020]
The brine supply pipes 7 and 8 are joined to a single brine supply pipe 11 provided with a temperature sensor 10.
[0021]
Here, the flow of the brine flows in the direction indicated by the arrow in FIG. That is, it circulates with the slurry brine production tank 1, the heat exchangers 4, 4, 4,... Of the showcase, and the brine transfer pumps 5A, 5B.
[0022]
The operation of the brine transport pumps 5A, 5B and the electromagnetic valves 9A, 9B, etc., with the above configuration will be described with reference to FIGS.
[0023]
In particular, in an open showcase with one or more sides open, after the end of business, the door is covered with a cover called a night cover and a weak cooling operation is performed to keep the products displayed in the showcase cold. Similarly, a showcase having a refrigeration operation is also performed at night.
[0024]
In the case of the present invention, the brine is actively solidified, that is, ice-making, especially at night when the electricity rate is low, and at this time, the brine is circulated and the weak cooling operation is performed. Accordingly, the running cost can be reduced.
[0025]
Then, as shown in FIG. 4, if the brine at the time of pull-down is all in a liquid state (in the drawing, the area described as liquid), the evaporator 3 is cooled in the refrigerator 2 to make ice, and the temperature Cooling is continued until the detected temperature of the sensor 10 reaches a predetermined temperature, that is, a temperature zone in which the periphery of the evaporator 3 is frozen (in the drawing, an area described as solid). In the solid state, the cooling by the refrigerator 2 is not performed, and the brine is cooled by the melting latent heat of ice.
[0026]
In addition, when the ice melts and changes from a solid state to a liquid / solid mixture state (in the figure, an area described as liquid + solid) and reaches a temperature at which it is determined that the amount of ice is extremely small, the refrigerator 2 is again used. To cool the evaporator 3 and make ice.
[0027]
Here, the cooling of the evaporator 3 is started, and after moving from the liquid state in FIG. 4 (area indicated as “liquid” in the figure) to the liquid / solid mixing, the ice making rate increases as shown in FIG. I will do it.
[0028]
In the normal operation state where ice is made and ice is present as described above, the brine transfer pump 5A is ON, the brine transfer pump 5B is OFF, and the electromagnetic valve 9A of the upper brine supply pipe 7 is open, as shown in FIG. The electromagnetic valve 9B of the lower brine supply pipe 8 is closed.
[0029]
That is, the brine from the upper part where the ice in the slurry brine generation tank 1 is circulated is supplied from the upper brine supply pipe 7 to the heat exchangers 4, 4, 4. .
[0030]
This is because ice is present in the upper portion of the slurry brine generation tank 1 and the brine temperature is sufficiently low due to the latent heat of melting of the ice, and the cold water immediately after heat exchange with ice from the upper brine supply pipe 7 is heated to the heat. This is because it can be sent to the exchanges 4, 4, 4.
[0031]
Then, every time a predetermined time elapses, the switching operation is alternately performed such that the brine transfer pump 5A is turned OFF and the brine transfer pump 5B is turned ON. In this way, the life of the brine transfer pumps 5A and 5B can be extended by performing the switching operation every predetermined time.
[0032]
Here, when the temperature at which it is determined that the amount of ice is small is reached, the evaporator 3 is cooled again, but since ice is not immediately generated, the brine transfer pump 5A is turned off as indicated by the dotted line in FIG. If the brine transfer pump 5B is ON, the stopped brine transfer pump 5A is turned ON while the brine transfer pump 5B remains ON.
[0033]
The operation of both the brine transfer pumps 5A and 5B is continued until the temperature sensor 10 detects a temperature zone in which the periphery of the evaporator 3 is frozen.
[0034]
In this way, when there is a possibility that the ice amount is insufficient and the cooling is insufficient, both brine transfer pumps 5A, 5B are operated to increase the brine circulation amount, and the showcase heat exchangers 4, 4, 4,. It is possible to prevent a decrease in the cooling capacity as much as possible.
[0035]
Further, by closing the electromagnetic valve 9A and opening the electromagnetic valve 9B, the bottom side of the slurry brine generating tank 1 without ice, that is, the cooler brine is circulated to the heat exchangers 4, 4, 4,. Supply.
[0036]
Here, in the state where the ice has disappeared, since warm water goes up and cold water goes down, the heat exchangers 4, 4, It is possible to prevent a decrease in the cooling capacity of 4.
[0037]
Next, the defrosting of the heat exchangers 4, 4, 4,... Will be described with reference to FIG.
[0038]
In normal operation with ice, for a predetermined time immediately before defrosting, the solenoid valve 9A is closed, the cooler brine supply from the upper brine supply pipe 7 is stopped, the solenoid valve 9B is opened, and the lower brine supply pipe is opened. Start hotter brine feed from 8.
[0039]
This is performed in order to preheat the heat exchangers 4, 4, 4,.
[0040]
When the defrost operation is started after a predetermined time has elapsed, the operation of the brine transport pumps 5A and 5B is stopped, the electromagnetic valve 9B of the lower brine supply pipe 8 is closed, and the electromagnetic valve 9A of the upper brine supply pipe 7 is opened. .
[0041]
Next, after the defrost operation is completed, the operation of the brine transfer pumps 5A, 5B is restarted, so that the lower temperature brine in the upper part of the slurry brine generation tank 1 can be immediately supplied to the heat exchangers 4, 4, 4,. it can.
[0042]
Therefore, when the goods displayed in the showcase are fresh foods in particular, the influence of heat due to defrost can be prevented as much as possible.
[0043]
In addition, although it is common to perform the defrost mentioned above with the electric heater etc. which were attached to the heat exchangers 4, 4, 4, ..., you may use another heating means. In the present embodiment, water is used as the brine, but other liquids may be used as long as they can be frozen. Furthermore, in the present embodiment, the circulating brine temperature is detected by the single temperature sensor 10, but another sensor such as a capacitance sensor is provided in the slurry brine generation tank 1 to check the presence or absence of ice. It may be detected.
[0044]
【The invention's effect】
As described above in detail, according to the invention of claim 1, in this way, in the slurry brine generation tank, a part of the liquid is solidified by making it lower than the temperature of the liquid, and the latent heat of fusion of this solid The liquid cooled in step 1 is circulated and supplied to the heat exchanger.
[0045]
Therefore, the heat exchanger can be stably cooled, and a desired cooling capacity can be exhibited even when the outside air temperature is high.
[0046]
Further, in the slurry brine generation tank, when there is a solid, the liquid located in the upper part has a low temperature and the liquid located in the lower part has a high temperature.
[0047]
Accordingly, it is possible to properly use a lower temperature liquid during normal operation and a higher temperature liquid during defrost.
[0048]
Furthermore, normally, at the time of cooling, the liquid located in the upper part of the slurry brine generation tank is sent to the heat exchanger, but when the solid in the slurry brine generation tank has completely melted, the liquid is positioned in the lower part of the slurry brine generation tank. Since the temperature of the liquid is lower, the temperature of the liquid flowing into the heat exchanger is detected by the temperature sensor, and when the temperature is equal to or higher than the predetermined temperature, the liquid is supplied to the heat exchanger from the lower brine supply pipe.
[0049]
Therefore, since the liquid at the optimum position in the slurry brine generation tank is supplied to the heat exchanger, a desired cooling capacity can be exhibited.
[0050]
According to the invention of claim 2, when the temperature of the liquid flowing into the heat exchanger becomes equal to or higher than a predetermined temperature, in order to prevent insufficient cooling capacity, heat exchange is performed to increase the flow rate by operating a plurality of transport pumps. The vessel can exhibit the desired cooling capacity.
[0051]
According to the invention of claim 3, immediately before defrosting, the higher temperature liquid in the brine generation tank, that is, the lower liquid is supplied from the lower brine supply pipe to the heat exchanger and preheated.
[0052]
Therefore, the transition to defrost can be performed smoothly.
[Brief description of the drawings]
FIG. 1 is a cooling circuit according to the present invention.
FIG. 2 is an operation diagram of a pump and a solenoid valve with and without ice.
FIG. 3 is an operation diagram of a pump and a solenoid valve at the time of defrosting.
FIG. 4 is a relationship diagram between brine temperature and cooling time.
FIG. 5 is a diagram showing the relationship between the ice making rate of brine and the brine temperature.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Slurry brine production tank 2 Refrigerator 4 Heat exchanger 5A, 5B Conveyance pump 7 Upper brine supply pipe 8 Lower brine supply pipe

Claims (3)

In a brine showcase in which the showcase is cooled using a liquid, the slurry brine generation tank that cools the liquid with a refrigerator and solidifies a part of the liquid by freezing, and the slurry brine generation tank A pump for circulating and supplying the liquid cooled in the heat exchanger of the showcase, a brine supply pipe for supplying the upper liquid in the slurry brine generation tank to the heat exchanger, and a slurry brine generation tank A lower brine supply pipe for supplying the lower liquid in the heat exchanger to the heat exchanger, and a temperature sensor is provided between the slurry brine generation tank and the heat exchanger, and the detected temperature of the temperature sensor is a predetermined temperature or higher. If present, the brine showcase is characterized in that liquid is supplied to the heat exchanger from the lower brine supply pipe.   In addition to providing a plurality of transport pumps, a temperature sensor is provided between the slurry brine generation tank and the heat exchanger. The brine showcase according to claim 1, wherein:   The brine showcase according to claim 2, wherein the liquid is supplied from the lower brine supply pipe to the heat exchanger immediately before defrosting of the heat exchanger.

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