JPH05133671A - Multiple temperature zone open showcase - Google Patents

Abstract

PURPOSE:To easily obtain a multiple temperature zone open showcase having a greater temperature difference and a simplified structure by forming at an opening part of a specific area an internal air curtain of temperature different from that of an external air curtain. CONSTITUTION:There is provided an open showcase wherein an air flow passing through an evaporator 4 connected with a compressor for compressing a refrigerant and a condenser is guided in a laminar flow to an opening part of an open showcase, and an air curtain is formed at the opening part to hold the interior of the same at predetermined temperature. A plurality of areas Z1, Z2 are provided on the open showcase, and an external air curtain 13 common to an opening 1a in those areas is formed and an internal air curtain 14 of a different temperature from that of the external air curtain 13 in the opening in the specific area and inside the external air curtain 13. Further, a plurality of areas of different temperatures are provided in the open showcase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open showcase for holding products at a predetermined temperature.

[0002]

2. Description of the Related Art Refrigerated open showcases mainly for daily products such as kneaded products, tofu, noodles, etc. are set at 5 to 10 degrees Celsius, and so-called green products such as dairy products, vegetables, fruits and vegetables are set. The main target refrigerated open showcase is set at 5-8 degrees Celsius. However, recently, the demand for lunch boxes has been rapidly increasing mainly at convenience stores, and there is a strong demand for the development of an open showcase that can sell bento, rice balls, sushi stuffed foods, prepared foods, etc. in addition to the conventional daily products. However, the optimum temperature range for bento such as cooked rice is 15 to 18 degrees Celsius, which is significantly different from the above-mentioned optimum temperature range.

[0003] Therefore, conventionally, the sandwich case is set to an appropriate temperature by the user by the temperature adjustment volume, or the case is once cooled to 5 to 10 degrees Celsius and the heater is heated to 15 to 18 degrees Celsius. I was dealing with it. In the former case, the differential of the temperature inside the refrigerator is too large, and the temperature inside the refrigerator becomes one temperature zone.
There was a drawback that daily products such as paste products, tofu, noodles, etc. could not be sold in the same warehouse. In the latter case, although there are two temperature zones, once cooled, it is heated again, so that not only the power consumption increases but also the number of parts increases and the initial cost increases. Further, since the inside of the refrigerator is dried, there is a drawback that the wetness which is important for the taste of cooked rice is impaired.

[0004]

That is, when the conventional sandwich-dedicated case for sandwiches is set at an appropriate temperature by the user with a temperature adjustment volume, it is used as a lunchbox centering on cooked rice. Is too large, and the temperature inside the storage is even higher than that, so there is a drawback that daily products such as kneaded products, tofu and noodles cannot be sold in the same storage. In the method of raising the temperature of once cooled to 15 to 18 degrees Celsius with a heater, there are two temperature zones, but since the once cooled is reheated, not only the power consumption increases but also the number of parts increases and the initial cost increases. To do. Furthermore, since the inside of the refrigerator is dried, there is a drawback that the wetness, which is important for the taste of cooked rice, is impaired, and it has been a problem to solve these drawbacks.

[0005]

As a concrete means for solving the above-mentioned problems of the prior art, the present invention provides an open showcase of an air flow passing through an evaporator connected to a compressor for compressing a refrigerant and a condenser. In an open showcase in which the interior of the open showcase is guided in a laminar flow manner and an air curtain is formed in the opening to maintain the inside at a predetermined temperature, the open showcase is provided with a plurality of areas and the plurality of areas are opened. A common external air curtain is formed on the interior of the open area, and an internal air curtain having a temperature different from that of the external air curtain is formed inside the external air curtain at the opening of a specific area. A multi-temperature zone open showcase characterized by the provision of an area

O of the fan forming the external air curtain
N, OFF or output control, ON / OFF or output control of the fan that forms the internal air curtain, and ON / OFF or output control of the compressor are provided in all or part of the multi-temperature zone open showcase. By doing so, the above-mentioned problems of the conventional technique are solved.

[0007]

[Function] Since an air curtain having a temperature different from that of the external air curtain is formed as an internal curtain in a specific area inside the external air curtain provided in common in each area, the temperature of the open showcase having a plurality of temperature zones Management is easier and temperature stability is improved.

[0008]

【Example】

(Embodiment 1) An embodiment of the multi-temperature zone open showcase according to the present invention will be described with reference to FIG. 1. The multi-temperature zone open showcase A is a main body 1 made of a heat insulating material having an opening 1a formed in the front surface. It consists of

Main body 1 including front plate 1f, bottom plate 1b, top plate 1c, left and right side plates 1e, 1e (not shown) and back plate 1d.
Is provided with an inner wall 3 along the front plate 1f, the bottom plate 1b, the top plate 1c, and the back plate 1d, with a duct 2, and a notch is formed in the lower part of the center of the inner wall 3 here. An evaporator 4 connected to a compressor for compressing the refrigerant and a condenser (both not shown) is provided.

Further, the inner wall 6 is provided in the lower half of the inside of the inner wall 3 with the duct 5a, and the inner wall 6 is provided in the upper half with the duct 5b. The duct 5a and the duct 5b are provided. The boundary of the vertical portion between and is partitioned openably and closably by an air curtain partition 8a attached to the area partition plate 8. The lower side of the area division plate 8 is the area Z1,
The upper side is the area Z2, the duct 5a is provided with the internal air curtain fan 7, and the duct 2 is provided with the external air curtain fan 9 on the side of the bottom plate 1b. Reference numeral 10 is a shelf on which the product 11 is placed, and reference numeral 12 is the product 1
It is a fluorescent lamp that illuminates 1.

Since the embodiment of the multi-temperature zone open showcase according to the present invention is constructed as described above, the air sucked from the suction port 2a of the duct 2 is urged by the external air curtain fan 9. Then, the temperature is lowered while passing through the side surface of the evaporator 4 and is blown downward from the upper outlet 2b to form a layered external air curtain 13 that covers the openings of the areas Z2 and Z1 and that of the duct 2 below. The air is sucked into the duct 2 from the suction port 2a and circulates.

On the other hand, the air sucked from the suction port 5a1 of the duct 5a is urged by the internal air curtain fan 7,
While passing through the evaporator 4, the temperature is lowered and is blown downward from the middle-stage air outlet 5a2 to form a layered internal air curtain 14 that covers the opening of the area Z1 and extends from the inlet 5a1 of the lower duct 5a to the duct 5a. It is inhaled and circulates.

In FIG. 1, a dashed arrow 15 fully opens the air curtain partition 8a, passes air from the duct 5a through the duct 5b, and blows it out through another upper outlet 5b2. The area Z2 is the same as the area Z1. It is a flow that has been brought to the temperature of.

The temperature inside the refrigerator is controlled by the circuit shown in FIG. In FIG. 3, the inside temperature sensor 16 is arranged in the inside of the above-mentioned inside, is connected to the thermo controller 17, and compares the inside temperature range set by the thermo controller with the signal from the inside temperature sensor 16. Then, the compressor 19 for compressing the refrigerant via the relay 18 is turned on / off to control the internal cold storage temperature.

FIG. 4 shows the internal temperature pulldown and the thermocycle. In FIG. 4, the vertical axis represents the internal temperature T and the horizontal axis represents the time t. A curve X shows the temperature of the area Z2 set to, for example, 15 to 18 degrees, and a curve Y shows the temperature of the area Z1 set to, for example, 5 to 10 degrees. When the power is turned on, the pull-down cycle is up to t1, and after t1, a steady thermocycle is started.

When time elapses to t1, the compressor 19 is stopped at the relay 18 by the thermo controller 17 in response to the signal from the inside temperature sensor 16 of the area Z1.
The temperature of the area Z1 begins to gradually increase from y1, and when the temperature inside the area Z1 reaches y2, the inside temperature sensor 16
The compressor 19 is activated by the signal of and the temperature inside the refrigerator enters the next lowering cycle.

The temperature of the area Z2 draws a curve having almost the same phase as the thermocycle of the area Z1, and the temperature gradually starts to rise from the temperature x1 at time t1 and reaches the temperature x2 at time t2. It is activated and enters the next descending cycle.

Since the temperature of the outer air curtain 13 is higher than the temperature of the inner air curtain 14, the temperature change during the thermocycle is small and the differential of the area Z2 can be set small.

These settings are made by setting the air flow rate, air speed and temperature of each air curtain, for example, the capacity of the refrigeration unit, the capacity of the evaporator, the evaporator passage area of each air flow, the number of fans, and the fan ducts. It can be realized relatively easily by adjusting the position in the inside, the flow resistance of the air flow (for example, the air curtain partition 8a), and the like.

In one embodiment according to the present invention, the air curtain is doubled, but it can be tripled to provide a freezing area, a refrigerating area, a high temperature refrigerating area, etc., and a multi-temperature zone open showcase. Optimal.

The open showcase A'shown in FIG.
Is an open showcase with a structure in which the opening in the upper area Z2 is covered with a double air curtain and the opening in the lower area Z1 is covered with a single air curtain. The open showcase shown in Fig. 1 It has a structure in which the upper and lower sides of A are just reversed.

That is, a notch is formed in the upper side of the inner wall 3 which forms the duct 2 with the main body 1, the evaporator 4 is installed therein, and the internal air curtain fan 7 is provided in the upper duct 5a. External air curtain fans 9 are installed in the upper ducts 2, respectively, the upper area Z2 is closed by the two layers of the outer air curtain 13 and the inner air curtain 14, and the lower area Z1 is the outer air curtain 13 only. It is a closed structure. The operation and the like are similar to those of the embodiment of FIG.

(Embodiment 2) A second embodiment according to the present invention will be described with reference to FIGS. FIG. 5 shows FIG.
FIG. 7 is a block diagram of a control system incorporated in the multi-temperature zone open showcase of FIG. 6, and FIG. 6 is a diagram showing the progress of the internal temperature in this case.

In FIG. 5, reference numeral 21 is an area Z in FIG.
Controller 1 which is a low temperature inside sensor installed in 1
7, the compressor 19 connected to the evaporator 4 via the relay 18 is turned on and off by detecting the upper and lower limits of the low temperature side internal temperature setting range. On the other hand, the high temperature side internal compartment sensor 22 is arranged in the area Z2 in FIG. 1 and detects the upper and lower limits of the high temperature side internal compartment temperature setting range to turn on and off the external air curtain fan 9. The internal air curtain fan 7 is constantly rotating.

Since the second embodiment of the present invention is constructed as described above, the control method and operation will be described with reference to FIG. In FIG. 6, the vertical axis represents the internal temperature T and the horizontal axis represents the time t. Curve X is, for example, 1 at the top of the cabinet
Showing the temperature of the Elias Z2 set to 5 to 18 degrees,
The curve Y shows the temperature of the area Z1 in the lower part, which is set to 5 to 10 degrees, for example. When the power is turned on, the pull-down cycle is up to t3, and after t3, a steady thermocycle is entered.

X1 is the lower limit set temperature (eg 15 degrees) of the area Z2, and x2 is the upper limit set temperature (eg 18 degrees).
Is. y1 is the lower limit set temperature of the area Z1 (for example, 5
And y2 is the upper limit set temperature (for example, 10 degrees). C is a curve showing the temperature at the outlet 2b of the external air curtain 13, and S is the internal air curtain 14.
Is a curve showing the temperature at the air outlet 5a2, and E is a curve showing the temperature at the inlet 5a1 of the internal air curtain 14.

When the power is turned on and time t1 is reached, the temperature at the outlet 2b of the external air curtain 13 becomes TC1.
Therefore, the temperature of the high temperature side area Z2 reaches x1 and the external air curtain fan 9 is stopped according to the instruction of the controller 17 by the signal of the high temperature side inside sensor 22, so that the temperature of the area Z2 rises. At the beginning, at t2, the temperature reaches x2 degrees, and thereafter, this cycle is repeated and the steady state is entered.

At time t3, the temperature at the outlet 5a2 of the internal air curtain 14 drops to TE1, and the temperature at the inlet 5a1 of the internal air curtain 14 drops to TS1.
Temperature reaches y1 and the compressor 19 is stopped according to an instruction from the controller 17 in response to the signal from the low temperature side inside sensor 21.

Therefore, the temperature of the area Z1 on the low temperature side begins to rise and reaches y2 degrees at t4, and the temperature at the outlet 5a2 of the internal air curtain 14 and the temperature at the suction port 5a1 of the internal air curtain 14 both enter the downward cycle. Therefore, the temperature of the area Z1 on the low temperature side also enters the descent cycle, and thereafter enters a steady state in which this cycle is repeated.

Therefore, the internal temperature of the high temperature side area Z2 is always within the range of x1 to x2 degrees, and the internal temperature of the low temperature side area Z1 is within the range of y1 to y2 degrees.

(Embodiment 3) Next, a third embodiment in which the low temperature side load may be light and the high temperature side load may be heavy,
A description will be given based on FIGS. 7 and 8.

FIG. 7 is a block diagram of a control system incorporated in the multi-temperature zone open showcase of FIG. 1, and FIG. 8 is a diagram showing the progress of the internal temperature in this case. In FIG. 7, reference numeral 21 denotes a low temperature inside chamber sensor arranged in the area Z1 of FIG. 1, which is connected to the controller 17 and detects the upper and lower limits of the low temperature side inside temperature setting range to generate ON and OFF signals. The high temperature side internal compartment sensor 22 is arranged in the area Z2 in FIG. 1, detects the upper and lower limits of the high temperature side internal compartment temperature setting range, and turns on the external air curtain fan 9 via the contact M3.
N, OFF.

The external air sensor 39 detects the temperature at the outlet 2b of the external air curtain 13 to turn it on and off.
Generate an F signal.

The control method and operation will be described with reference to FIGS. 7 and 8. In FIG. 8, the vertical axis represents the internal temperature T and the horizontal axis represents the time t. In the area of, the low temperature side lower limit temperature detection circuit 34 and the external air sensor 3 connected to the low temperature side inside sensor 21.
External air set temperature lower limit temperature detection circuit 32 connected to 9
However, since neither OFF signal is output, NAND gate 3
5, the AND gate 38 does not turn on, the relay 18 continues to turn on through the normally closed contact M1, and the compressor 19 continues to rotate.

On the other hand, the internal air curtain fan 7 is
The OR gate 30 allows the low temperature side lower limit temperature detection circuit 34 to be detected.
OFF signal and low temperature side upper limit temperature detection circuit 33 by
ON and OFF are controlled by the ON signal by.

Next, in the region b from time t1 to t3, when both the external air set temperature lower limit temperature detection circuit 32 and the low temperature side lower limit temperature detection circuit 34 output OFF signals,
The NAND gate 35 turns ON, the latch circuit 36 outputs an ON signal, the OR gate 30 outputs, and the contact M2 turns ON.
Then, the internal air curtain fan 7 continues to rotate, and at the same time, the AND gate 38 is turned on by the OFF signal of the lower temperature side lower limit temperature detection circuit 34, the contact M1 is turned off, and the compressor 19 stops rotating.

Next, when the external air sensor 39 reaches or exceeds the external air curtain set lower limit temperature, the external air sensor 3
The external air curtain setting lower limit temperature detection circuit 31 connected to 9 outputs an ON signal, the AND gate 37 is turned ON by the ON signal of the latch circuit 36, and the compressor 19 is started.

In the region c after the time t3, the temperature of the external air curtain 13 becomes equal to or lower than the lower limit temperature set by the external air curtain, and the thermocycle is repeated. The external air curtain fan 9 is turned on by the sensor 22 inside the high temperature side,
It is turned off.

Normally, the latch circuit 6 is released at the time of defrost. The characteristics of the inside temperature due to the above-described operation will be described with reference to FIG. 8. In the region a up to t1, that is, the pull-down region, the internal air curtain outlet temperature E decreases to TE1, and during this period, the inside temperature of the low temperature side falls. Y reaches the lower temperature side lower limit temperature y1 and enters into a thermocycle which goes up and down between the lower temperature side lower limit temperature y2. During this period, the internal air curtain suction temperature E is the internal air curtain blowout temperature E.
It goes up and down in almost the same phase.

The temperature C of the external air curtain 13 is t
At 1 the external air curtain set lower limit temperature is reached and the high temperature side internal sensor 22 controls the external air curtain fan 9 by turning it on and off, so after time t1 the thermocycle between the external air curtain set temperature and the external air curtain set temperature is entered. ..

At the time t1, the internal temperature X on the high temperature side reaches the internal temperature lower limit temperature x1 on the high temperature side, reaches the internal temperature upper limit temperature x2 on the high temperature side a little before t2, and the fan 9 for the external air curtain is activated, t3. Thereafter, the thermocycle with the lower temperature limit x1 on the high temperature side is entered. In this case, the curve of the temperature C of the external air curtain and the curve of the internal temperature X of the high temperature side are out of phase.

In each of the above embodiments, the evaporator 4 is used.
Is shared by the external air curtain 13 and the internal air curtain 14, but it is also possible to form an air curtain having different temperatures by providing an auxiliary evaporator.

[0043]

As described above, the present invention is an open showcase in which an external air curtain common to all areas and an internal air curtain of different temperature are provided inside the air curtain, so that the structure is simple. Moreover, it is easy to make an open showcase with multiple temperature zones with a large temperature difference, and it is easy to keep the temperature differential small.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment.

FIG. 2 is an explanatory diagram showing a modification of the first embodiment.

FIG. 3 is a block diagram of a control system of the first embodiment.

FIG. 4 is an explanatory diagram of temperature characteristics of the first embodiment.

FIG. 5 is a block diagram of a control system of a second embodiment.

FIG. 6 is an explanatory diagram of temperature characteristics of the second embodiment.

FIG. 7 is a block diagram of a control system of a third embodiment.

FIG. 8 is an explanatory diagram of temperature characteristics of the third embodiment.

[Explanation of symbols]

 1 Main body 2, 5a, 5b Duct 3 Middle wall 4 Evaporator 6 Inner wall 7 Internal air curtain 8 Area division plate 8A Air curtain partition 9 External air curtain fan 10 Shelf 11 Product 12 Fluorescent lamp 13 External air curtain 14 Internal air curtain 17 Relay 18 Compressor 21 Internal temperature sensor 22 Thermo controller

Claims (2)

[Claims] 1. An air flow passing through an evaporator connected to a compressor for compressing a refrigerant and a condenser is introduced into an opening of an open showcase in a laminar flow manner, and an air curtain is formed at the opening to form an internal space. In an open showcase that is maintained at a predetermined temperature, a plurality of areas is provided in the open showcase, a common external air curtain is formed in the openings of the plurality of areas, and the external air is opened in the openings of specific areas. A multi-temperature zone open showcase, wherein an inner air curtain having a temperature different from that of the curtain is formed inside the outer air curtain, and a plurality of areas having different temperatures are provided in the open showcase. 2. A fan O forming an external air curtain.
2. The multi-temperature zone according to claim 1, wherein all or part of N, OFF or output control, ON, OFF or output control of a fan forming an internal air curtain, and ON, OFF or output control of a compressor are shared. Open showcase.