JPH0697132B2 - Low temperature showcase - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention provides two evaporators each provided with an electric heater for defrosting on a lower surface which is a surface on the air inlet side in a passage for cold air circulation. Regarding the arranged low temperature showcase.

(B) Prior art JP-A-60-256773 and JP-A-60-256776 disclose a partition plate defining a storage chamber having one side as an opening for storing and taking out a product, and the storage chamber. A cold air circulation passage that is formed around and guides the cold air that is forcedly circulated to the opening, an inner passage that divides the back region of the passage into an inner narrow passage and an upper narrow passage, and a lower wide passage that expands upward. A first divided plate having good heat conduction forming a passage and an outer passage having a narrow passage at the lower side; and a defrost heater provided on each of the above-mentioned expanded passages and partially overlapping with each other in a plan view, and a defrost heater on an air inlet surface. A second division which is disposed on the front surface of the first evaporator in the inner passage and the first and second evaporators and which forms an auxiliary passage having an upper surface opening between the rear wall of the partition plate and good heat conduction. A low temperature shovel comprising a plate and a plurality of holes formed in the lower part of the back wall of the partition plate to connect the auxiliary path and the lower part of the storage chamber. Configuration case is disclosed.

(C) Problems to be Solved by the Invention According to the above-mentioned conventional technique, since the lower end of the dividing plate is substantially the same height as the lower surface which is the air inlet surface of the first evaporator,
During the defrosting operation of the evaporator, a part of the return cold air heated by the downward heat of the radiant heat of the defrosting heater provided on the air inlet surface of the first evaporator passes through the lower end of the dividing plate to the second side from the outer path.
It will flow to the evaporator. For this reason, the defrosting heat amount for the first evaporator during defrosting becomes insufficient and the defrosting time becomes longer, and the refrigeration load on the second evaporator during cooling increases, and the heat of the defrosting heater is effectively used. There are also problems that cannot be used, and that it is troublesome to divide the cool air evenly into a plurality of evaporators.

(D) Means for Solving the Problems The present invention is intended to solve the above-mentioned problems, and as a means thereof, the back area of the cold air circulation passage is divided into an inner passage and an outer passage. A plate and an electric heater for defrosting on a lower surface which is a surface on the air inlet side, respectively, and a first evaporator arranged in the inner path, and a first evaporator arranged above the first evaporator and in the outer path. A second evaporator, a common blower for sending cool air to both the first and second evaporators, and a lower part of the dividing plate, which extends below the electric heater of the first evaporator. In addition, a low temperature showcase including an extension portion that extends to the windward side opposite to the lower surface of the first evaporator and divides the cool air from the common blower into the inner passage and the outer passage. Is.

(E) Action According to the embodiment, the extending portion (32) of the dividing plate (27) has the first,
One of the functions of splitting the return cold air flowing toward the second evaporators (14) (15) into the inner passage (28) and the outer passage (29) on the upstream side of the air inlet surface of the both evaporators. Thus, during the defrosting operation of the first evaporator (14), the radiant heat directed downward from the electric heater is reflected upward.

(F) Embodiment An embodiment of the present invention will be described below with reference to the drawings.
Reference numeral (1) shown in the figure is a low temperature showcase in which a main body is composed of a heat insulating wall (3) having an opening (2) for storing and taking out products on the front surface, which is more suitable than the inner wall of the heat insulating wall (3). By sequentially arranging the first and second partition plates (4) and (5) at intervals, the first passage (6) for cold air circulation and the second passage (7) for protection air circulation. ), A storage chamber (9) having a plurality of shelves (8), and outlets (1) and (2) of the first and second passages (6) (7) along the upper edge longitudinal direction of the opening (2). 1
0) (11) and the inlets (12) of the first and second passages (6) (7) facing the outlets (10) (11) along the longitudinal direction of the lower edge of the opening (2). (13) and are formed.

The first passage (6) has two plate fin-shaped first and second evaporators (14) and (15) and a surface on the air inlet side of the corresponding evaporator of the two evaporators. The first and second electric heaters (16) (17), which are respectively provided on the lower surface and are energized when the corresponding evaporators (14) (15) are defrosted, and an axial flow type of several rows in a row. A first blower fan (18) is arranged, and a plate fin type third evaporator (19) is provided in the second passage (7).
And an axial-flow-type second blower fan (20).

Since the back part of the first partition plate (4) is formed with an inclined part (21) that is inclined rearward and downward and the bottom wall part is formed with a vertical rising part (22), In the back and bottom areas of the first and second passages (6) and (7), widened passages (23) (24) (25) (26) are formed, and the first passage (6) is formed. Evaporator (14) on the widening (23) in the back area of
(15), the wide passage (24) in the back area of the second passage (7) has an evaporator (19) and the wide passage (2 in the bottom area of the first passage (6) (2).
The first blower fan (18) is arranged at 5), and the second blower fan (20) is arranged at the widening (26) in the bottom area of the second passage (7).

The metal (27) is arranged in the expanded passage (23) of the first passage (6) and divides the expanded passage (23) into an inner passage (28) and an outer passage (29) made of stainless steel. A split plate made of steel, a slanting portion (30) slanting downward to the rear is formed in the center, and the first evaporator (14) is provided in the lower portion extending below the first electric heater (16). An extension (32) having a flange (31) facing the lower surface of the. Since the dividing plate (27) forms the inclined portion (30), the lower part of the inner path (28) and the upper part of the outer path (29) are the first,
Widening path (3) for arranging the second both evaporators (14) (15)
3) (34), while the upper part of the inner path (28) and the lower part of the outer path (29) are narrow paths (3
5) (36) In addition, the inner path (2
The entrance width of 8) is about twice the entrance width of the outer road (29), while the exit width of the outer road (29) is about twice the exit width of the inner road (28). The amount of ventilation of both evaporators (14, 15) in a frost-free state is constant.

Since the first partition plate (4) and the dividing plate (27) are formed with the inclined portions (21) (30) in the same direction,
When the arrangement state of the third evaporators (14), (15) and (19) is viewed two-dimensionally, the front half of the third evaporator (19) and the rear half of the second evaporator (15) overlap each other, and The rear half of the first evaporator (14) overlaps the front half of the two evaporators (15), and three evaporators (14) (15) (19) are arranged. Instead, the configuration is such that the three evaporators (14), (15) and (19) can be arranged substantially in the space for disposing the two evaporators (14) and (19).

(37) is a metallic third partition plate arranged on the front surface of the first evaporator (14).
The upper part opens between the back wall (38) and the lower part of the partition plate (5),
A bypass (39) is formed with the lower part closed. Reference numeral (40) is a large number of through holes formed in the lower portion of the back wall (38) for connecting the side passage (39) and the lower area of the storage chamber (9).

FIG. 2 shows a refrigerating apparatus for cooling the low temperature showcase (1), which comprises a refrigerant compressor (41), an air-cooled condenser (42), a liquid receiver (43) and a dryer ( 44), sight glass (45), first to third solenoid valves (46) (47) (4
8), first to third expansion valves (49) (5) that are pressure reducing devices
0) (51), the first to third evaporators (14) (15) (1
9), a gas-liquid separator (52), a high-pressure gas pipe (53), a high-pressure liquid pipe (54), and three high-pressure liquid branch pipes (55) (56) (57) whose inlets are connected to the high-pressure liquid pipe. ) Three low pressure liquid pipes (58) (59)
(60) By connecting the three low pressure gas branch pipes (61) (62) (63) and the low pressure gas pipe (64) to which the outlets of the respective low pressure gas branch pipes are connected in an annular shape, Thru | or each 3rd evaporator (14) (15) (19) respond | corresponds in series with the 1st thru | or each 3rd each solenoid valve (46) (47) (48) and expansion valve (49) (50) (51). And is configured as a closed circuit having a parallel relationship with each other.

FIG. 3 shows another embodiment of the refrigerating apparatus, and the first to third solenoid valves (46) (47) (48) and the first electromagnetic valve (46) shown in FIG.
To the third expansion valves (49) (50) (51) instead of the first to third electronic expansion valves (6), which have an opening / closing function and a pressure reducing function and whose valve shaft is vertically movable by a stepping motor.
5) (66) (67) may be used.

The first to third solenoid valves (46) (47) (48) are those whose opening and closing are controlled by a temperature switch such as a timer or a thermostat (not shown) called a duty cycler. During the cooling operation of the evaporator (14) (15), the first and second solenoid valves (46) (47) are opened and the third solenoid valve is opened.
The solenoid valve (48) is closed, and the first and second evaporators (14) are also closed.
The supply of the refrigerant to (15) is interrupted, and the third evaporator (19)
At the time of so-called duty-off or thermo-off in which the refrigerant is supplied to the first and second solenoid valves (46) (47) are closed, the third solenoid valve (48) is opened, and the first evaporator (14) is further opened. Is in the defrosting operation and the second and third evaporators (15) (19) are in the cooling operation, the first solenoid valve (46) is closed and the second and third solenoid valves (47) (48) are open. Further, when the second evaporator (15) is in the defrosting operation and both the first and third evaporators (14) (19) are in the cooling operation, the second solenoid valve (47) is closed, the first and the second are. The operation for opening the three-way solenoid valves (46) (48) is performed.

Next, the operation of the low temperature showcase (1) will be described.

During the cooling operation, both the first and second solenoid valves (46) (47) are open, and the first and second expansion valves (49) (50) to the first and third evaporators (14) (15). ) Is supplied with the decompressed liquid refrigerant, and the cold air that has undergone heat exchange in the first and second evaporators (14) and (15) is supplied by the first blower fan (18) to the solid line in FIG. Opening (2) by forced circulation as shown by the arrow
A cool air curtain (CA) is formed on the inside to cool the storage chamber (9) to a predetermined temperature, while the second blower fan (2)
0) Therefore, the air forcedly circulated as indicated by the dashed line in FIG. 1 is formed outside the air curtain (CA) at the opening (2) as a guard air curtain (GA) for protecting the air curtain from the outside. It

In this cold air circulation, the cool air returning from the suction port (12) to both the first and second evaporators (14) (15) is supplied to the inner passage (28) at the extending portion (32) of the dividing plate (27). , The outer passage (29), respectively, and after passing through the first and second evaporators (14, 15) respectively, they merge and are blown out from the outlet (10) toward the opening (2). . On the other hand, a part of the cold air passing through the first evaporator (14) passes through the side passage (39) and the through hole (40) and crosses the lower space of the storage chamber (9), and then the air curtain (CA).
It joins the cold air that has formed to reach the suction port (12).

Next, the first electric heater (16) is energized during the defrosting operation of the first evaporator (14), and the second electric heater (17) is energized during the defrosting operation of the second evaporator (15). Defrost the frost on the corresponding evaporator. During the defrosting operation, cold air and air are forcedly circulated as shown in FIG.

During the defrosting operation of the first evaporator (14), the downward heat of the radiant heat from the first electric heater (16) is extended by the extension portion (32) to the air inlet side of the first evaporator (14). Will be reflected in the plane direction.

According to such a configuration, the extending portion (32) of the dividing plate (27) allows the return cool air toward the first and second evaporators (14) and (15) to face the air inlet side of both evaporators. Inner road upstream from (28)
And the outside passage (29), while at the time of the defrosting operation of the first evaporator (14), the radiant heat directed downward from the electric heater (16) is reflected upward.
During the cooling operation, the cold air is equally distributed to the inner passage (28) and the outer passage (29), and the first and second evaporators (14) (1)
In addition to promoting heat exchange by 5), almost all the heat from the electric heater (16) can be guided to the first evaporator (14) during the defrosting operation of the first evaporator (14). Therefore, the defrosting time of the first evaporator (14) can be shortened, and the defrosting heat source can be effectively used.

(G) Effect of the Invention According to the invention of the present application, a blower for each evaporator is required as in the conventional one in order to divert the cool air to a plurality of evaporators by having the extending portion having the above-described structure. Without using the common blower, the cool air can be distributed evenly, which simplifies the structure and installation work, and at the time of defrosting the first evaporator, the radiant heat from the electric heater can be reflected by the extension part. Can almost lead to the first evaporator,
The defrosting time of the first evaporator becomes short, and the defrosting heat source can be effectively used.

[Brief description of drawings]

Each of the drawings shows an embodiment of the low temperature showcase of the present invention,
FIG. 1 is a vertical sectional view, and FIGS. 2 and 3 are refrigerant circuit diagrams of a refrigerating apparatus. (6) ... passage, (14) ... first evaporator, (15) ... second evaporator, (16) (17) ... electric heater, (27) ... dividing plate, (28) ... … Inner road, (29) …… outer road, (32)…
... extension part.

Claims (1)

[Claims] 1. A dividing plate that divides a back area of a cold air circulation passage into an inner passage and an outer passage, and an electric heater for defrosting on a lower surface which is a surface on an air inlet side, and is arranged in the inner passage. A first evaporator, a second evaporator arranged above the first evaporator and in the outer passage, and a common blower for sending cool air to both the first and second evaporators in common. It is provided in the lower part of the dividing plate, extends below the electric heater of the first evaporator, and extends to the windward side opposite to the lower surface of the first evaporator, and cools air from the common blower to the inner passage. And a low temperature showcase including an extension part that divides into an outer path.