JPS6219670A - Low-temperature showcase - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a low-temperature showcase in which a forward-reversible blower fan and two evaporators are provided in a passage.

(b) Conventional technology Japanese Patent Application Laid-open No. 1983-47176 (F25D21106)
and Japanese Unexamined Patent Publication No. 178176/1983 (F25D2110
6)KG'! , -8 side〈An insulating wall with an opening for storing and taking out products, and an insulating wall arranged at an appropriate distance from the inner wall of the insulating wall, facing each other through the opening, and when one side is an air outlet, the other side is (1) a partition plate formed in the heat insulating wall that is a passage and a storage room having ventilation holes serving as suction ports at both ends; a forward-reversible blower fan supported by a fan case that bisects the passage; and the fan. Two evaporators are provided between the case and both vents, and when one of the evaporators is in a cooling operation, the other is in a defrosting operation, and when one evaporator is in a defrosting operation, the evaporator is A low-temperature showcase is disclosed in which a container is defrosted with a high-temperature refrigerant that has passed through a condenser.

(c) Problems to be Solved by the Invention In the above-mentioned conventional technology, both evaporators that are operated for cooling alternately have an evaporation pipe that evaporates the reduced-pressure liquid refrigerant and a defrost pipe that passes the high-temperature refrigerant. In preparation, when one evaporator is being defrosted, the entire evaporator is heated by the defrosting pipe, so the temperature of the air passing through the evaporator during defrosting is high, which becomes a refrigeration load on the evaporator during cooling.
Storage chamber b'-problem b'-occurs that the temperature does not drop to the specified temperature,
In addition, because high-pressure refrigerant is passed through the defrost pipe to defrost regardless of the outside temperature, the temperature of the evaporator increases significantly during cooling, and furthermore, when switching from cooling to defrosting, Since there is residual liquid refrigerant in the evaporator tube, not only does the removal time become longer, but there is also the problem that there is a shortage of refrigerant in the evaporator during the cooling operation.

B) Means for Solving the Problems In order to solve the above problems, the present invention provides a heat insulating wall (3) having an opening (2) for storing and taking out products on one side thereof;
A passageway (7) which is arranged at an appropriate interval from the inner wall of the heat insulating wall and faces oppositely through the opening, and has a vent hole +51 (61) at both ends, and when one side is a blowout port, the other side is a suction port.
) and a partition plate (
4), a forward-reversible blower fan (9) supported by a fan case 001 that bisects the passage, and a blower fan (9) disposed between the fan case and both vents, one of which is in cooling operation. When two evaporators (II
A) (IIB), two vents (5) and (6), and two evaporators (IIA) and (IIB), which are respectively arranged between the two vents (5) and (IIB), and which are energized during defrosting operation of the corresponding evaporators. An electric heater (12AX12B) is disposed in the passage and located between both evaporators, and when the air temperature in the passage reaches b' - a predetermined temperature or higher while the air heater is passing, the electric heater ( 12A) (12B) A low temperature showcase (11) is provided which is equipped with a temperature detector (21) that stops energizing.

(e) Function: For example, during cooling operation of one evaporator (uB), an air heater (I2A) b'' that heats the other evaporator (nA), the airflow of the evaporator (IIA) when viewed from the direction of airflow circulation. The evaporator C
Among the cold air heat-exchanged in IIB), the cold air that forms a cold air curtain at the opening (2) has almost no thermal effect, and the temperature rises when it comes in contact with the outside air at the opening (2), leading to the air opening. (6) It is possible to defrost the evaporator (11 people) by heating the cold air that has passed through the evaporator (IIA).
During defrosting, the air heated by the electric heater (12A) gradually loses its latent heat while flowing from the upper end of the evaporator (IIA) to the lower end in order to thaw the frost. In addition, when the air temperature in the passage (7) reaches a predetermined temperature or higher due to the completion of defrosting of the evaporator (11A) or a rise in outside air temperature, the temperature is forcibly reduced regardless of the switching of the time switch (TS). Detector CD cuts off the power supply to the electric heaters (12 persons) to prevent an increase in the refrigerating load on the evaporator (IIB) during the cooling operation. Furthermore, the solenoid valve (26A) is closed during the cooling operation of the evaporator (IIB), and the residual liquid refrigerant of the evaporator 6 (IIA) during defrosting can be gradually recovered.

(F) Example The present invention will be explained in detail based on the drawings below. (1) shown in Fig. 1 has an opening (2) on the top surface for storing and taking out products.
This is an open-door low-temperature showcase whose main body is made up of a heat insulating wall (3) with a metal partition plate (4) arranged at an appropriate distance from the inner wall of the heat insulating wall (3). a passageway (7) having vent holes (5) and (6) at both ends facing each other through the opening (2) and one serving as an air outlet and the other serving as an inlet; It forms a chamber (8). (9) is a blower fan that can be rotated forward and backward;
It is supported by a fan case (10) which divides the front and rear parts into two. (IIA) and (IIB) are respectively disposed between the above-mentioned two ventilation holes +51f61 and the fan case a■, and are supported by the front wall (10) of the partition plate (4). 4A) or the back wall (4B), plate fin type evaporators (12 people) (12B) are arranged between both the vents (5H6) and both evaporators (IIA) (IIB), respectively. Electric heater for defrosting installed (13Q
Reference numeral 41 indicates a honeycomb-shaped rectifier installed at the vents (5) and (6), respectively, and Kasumi is provided at the back of the evaporator (11A) and connects it to the front wall (4A) of the partition plate (4). A partition plate (17) forming a space αe therebetween is provided at the front of the evaporator (11B) and forms a space (17) between it and the back wall (4B) of the partition plate (4).
The partition plate α9 forming 1υ is arranged in the storage chamber (8), and its front and back ends are connected to the front and back walls (4A) of the partition plate (4) (
4B), (21) is a mirror placed above the opening (2), and (21) is the rack supported by both the evaporators (11AX).
IIB), that is, in the vicinity of the blower fan (9), in the passage (7), and the air temperature 61 in this passage is
It is an attitude detector that outputs a signal to a temperature switch, which will be described later, and opens when the temperature is 53° C. or higher, and closes when the temperature is 5° C. or lower. Also, @ is a machine room formed below the heat insulating wall (3),
A refrigerant compression device, a condenser 24), and a blower fan (c), which together with the evaporators (IIA) and (IIB) constitute a refrigeration system, are installed.

Figure 2 shows the refrigerant circuit of the refrigeration system and the evaporator (11
In A), a solenoid valve (26A), an expansion valve (27 valves), and an evaporator (11B) have a t-magnetic valve (26B) and an expansion valve (27B) connected in series, and connected in parallel to each other. still,
(Mark 2 is a liquid receiver, and Gl is a gas-liquid separator. The opening and closing operations of both the electromagnetic valves (26A) and (26B) can be alternately switched by a timer.

3 and 4 show the electric circuit of the low temperature showcase (1), FIG. 3 is a three-phase 200V source circuit, and FIG. 4 is a single-phase 100Vli source circuit. In FIG. 3, (C
M) is a contact piece (52Ca) of an electromagnetic switch for a compressor, which will be described later.
The compressor motor (FM, ) is connected to the R, S, and T phases via ), and the compressor motor (FM, ) is connected between the R and S phases via the first tangent piece (IXa+) of the first auxiliary relay, which will be described later. (52C) is a thermostat (TH) that detects the temperature of the storage room (8), a high/low pressure switch (63PH), and a second tangent piece (xXa) of the first auxiliary relay.
and two overload relays (
This is an electromagnetic switch for a compressor connected between both R and T phases via OLR, ) (OLRt). Also, in the above Fig. 4, (SS) is an operation switch, (LX) (2X)
(3X) is the first. 2nd and 3rd auxiliary relays, (FM,)
Blower fan (9
) motor, (CR) surrounded by chain lines is internal power supply (ID),
This is a controller that houses a delay switch (LS), @degree switch (21a), and time switch (TS). The time switch (TS) is a timer (1) in control 1 (CR).
) is opened and closed every two hours, for example, and this time switch has two time switches connected in parallel.
, and both third auxiliary relays (2X) (3X) are connected in series. (2Xa l) is the second auxiliary relay (2Xa l)
The first contact piece of X) connects the solenoid valves (2
6 people) Contact either one of the contact points (a) and (b) of (26B). (2Xat) is the second auxiliary relay (2Xat).
X) is directly connected to the one-time switch Cυ for detecting the air temperature in the passage (7), and the respective contacts ( C) Contact either one of (d).

(3Xa) is the contact piece of the third auxiliary relay (3X).
The normal rotation contact (e) of the motor (FM2) of the blower fan (9) is connected in series to the delay switch (LS).
, is in contact with either one of the reversing contacts (f). Said delay switch (LS) t'! , within said side Xhei (CR) (7
) It is opened and closed by the signal from the delay 4-r (LT). The delay timer (LT) is activated from the time when the time switch (TS) is opened and closed, and
)b-The delay switch (LS) is closed after the time elapses, for example, 2 minutes, until it completely stops when switching from forward rotation to reverse rotation or vice versa. Low temperature showcase (based on
To explain the operation of 1), the operation switch (SS)
When the auxiliary relay (IX) is turned on, the first auxiliary relay (IX) is energized and both the first and second liquid pieces (IXas) (IXat) are closed, which causes the compressor electromagnetic switch (52C) to close.
is ONL, the contact piece (52Ca) of the lever is closed, and the compressor (c) is driven.In this state, if the time switch is in the b- position, the second and third auxiliary relays (2X
) C3X) b: Because it is de-energized, the first contact (2Xal) of the second auxiliary relay (2X) is the contact (b), the second contact (2Xa is the contact (d), Relay (3X
) is in contact with the reversing contact (f). As a result, the solenoid valve (26A) b' is energized and opens, supplying hydraulic liquid refrigerant to the evaporator (11A) and starting the cooling action, but since the air temperature in the passage (7) is high and is below 5°C. A close signal is sent from the VC@degree detector Cυ to the temperature switch (21a).

The electric heater (12B) is de-energized. Set'
When two minutes have elapsed since the operation switch (SS) was turned on, the delay switch (LS) b' is closed and the blower fan (9) is reversed.

The cold air heat-exchanged in the evaporator (IIA) is forcedly circulated as shown by the solid arrow in FIG. 1 to form a cold air curtain in the opening (2) and cool the storage chamber (8). This b-evaporator (
11 people) during the cooling operation.

When the air temperature in the passageway (7) falls below 5°C μ, the temperature switch (21a) bt is closed and the electric heater (12B) is energized.

The return cold air that reaches the evaporator (IIA) is heated.

When two hours have passed since the operation switch (88) was turned on, the timer (T) b- is output and the time switch (TS) is turned on.
is closed, and the delay timer (LS) is reset to open the delay switch (LS). Then.

Second. Both third auxiliary relays (2X) (3X) are energized.

The first one. Both second liquid pieces (2Xa1) (2Xa,) b
t contact the contacts (b) and (C) respectively, and the contact piece (3Xa
) comes into contact with the normal rotation contact (e) (accompanying this switching operation).

tWi valve (26B) bt opens and the reduced pressure liquid refrigerant b is supplied to the evaporator (IIB) and starts cooling action.
The electric heater (12A) is energized. When two minutes have elapsed after the switching operation, the delay timer (LT) outputs an output to close the delay switch (LS) and rotate the blower fan (9) in the normal direction. As the blower fan (9) rotates normally, the evaporator (11B)
) is forcibly circulated as shown by the chain line arrow in Figure 1, forming a cold air curtain in the opening (2) to cool the storage room (8), while the electric heater (12 people): r
: The so-called defrosting of the evaporator (IIA) is performed to gradually melt the frost that has adhered to the heated evaporator (IIA).

From then on, this cooling operation was performed alternately every two hours.

For example, during one evaporator (IIB) b'-cooling operation,
The other evaporator (11A) is in defrosting operation.

Therefore, according to the configuration 5, for example, one evaporation B (I
During the cooling operation of IB), the other evaporates! An electric heater (12A) bZ that heats the evaporator (IIA), a vent hole (6
), it has almost no direct thermal influence on the cold air that forms a cold air curtain at the opening (2) out of the cold air that has been heat exchanged in the evaporator (IIB). The evaporator (IIA) can be defrosted by heating the cold air that comes into contact with the outside air and passes through the vent (6) in step 2). The air heated by the heater (12A) is passed through the evaporator (1
During the period from the upper end to the lower end (1 person), the latent heat of K is gradually taken away to melt the frost (evaporator (IIA)
Temperature b after passing through the evaporator (11 people) until just before the end of defrosting
Z does not rise, and the temperature of the cool air returned from the evaporator (IIB) can be lowered. As a result, the refrigerating capacity of the evaporator (IIB) performing the cooling action can be reduced, and the defrosting efficiency of the evaporator W (IIA) performing the defrosting action can be improved. In addition, when the defrosting of the evaporator (11A) is completed or the outside air temperature rises, the time switch (TS)
Irrespective of the switching of It is possible to prevent an increase in the refrigeration load. Furthermore, the solenoid valve (26A) b' is closed during the cooling action of the evaporator (IIB), and the evaporator (IIB) is closed during the cooling operation of the evaporator (IIB).
Since the residual liquid refrigerant of IA) is also gradually recovered, a shortage of refrigerant in the evaporator (11B) may occur.
In addition to providing a stable cooling effect, the evaporator (11A
) becomes faster than in the case of liquid refrigerant, and the defrosting time of the evaporator (IIA) becomes faster.

Furthermore, both evaporators (IIA) (IIB) have partition plates αωα
Since a space (lecl) exists between the partition plate (4) and the partition plate (4) due to the force, heat is not directly transmitted from both sides to the partition plate (4) even during cooling or defrosting operation. As a result, the temperature throughout the storage chamber (8) can be maintained uniformly. (g) Effects of the Invention According to the present invention described above, the following effects bt are produced.

■ The electric heater that heats the evaporator during defrosting is located on the upwind side of the evaporator during defrosting and on the leeward side of the vent that serves as the suction port when viewed from the direction of the circulating cold air. It is possible to heat the evaporator during defrosting without having almost any thermal effect on the cold air that forms a cold air curtain at the opening of the cold air that has been heat exchanged with the air heater. As the latent heat is gradually taken away by the frost while passing through the evaporator during defrosting, the temperature does not rise too much; therefore, the temperature of the cold air returning to the evaporator during the cooling action can be kept low. As a result, the refrigerating capacity of the evaporator can be reduced.

■ When the temperature inside the passage rises above a predetermined temperature due to completion of defrosting of the evaporator or rise in outside air temperature, the electric heater is forcibly de-energized by the temperature sensor, so that the electric heater is de-energized during the cooling operation. An increase in the refrigerating load on the evaporator can be prevented.

■ Residual liquid refrigerant in the evaporator during defrosting can be recovered and used in the evaporator during cooling, so it is possible to eliminate the refrigerant shortage in the evaporator during cooling, and also to reduce the amount of refrigerant in the evaporator during defrosting. It is possible to speed up the promotion speed and shorten the defrosting time.

[Brief explanation of drawings]

All drawings are electrical circuit diagrams of the third product door 4 of the embodiment of the low-temperature showcase of the present invention. (2)...Opening, (3)...Insulating wall, (4)...
・Dividing board, (5) (6)...Vent, (7)...Aisle, (8)...Storage room, (9)...Blower fan, (
1G...Fan case. (IIA) (IIB)...Evaporator, (12A) (1
2B)...Electric heater, I21)...Temperature detector. Fig. 4 Fig. 3 Fig. 3 φ200V , Relationship with the case of the person making the amendment Patent application Name (188) Sanyo Electric Co., Ltd. 4, agent and 1 other person Address 2-18 Keihan Hondori, Moriguchi City Contact information: Telephone (Tokyo) 835-1111 Nakagawa 5, resident at Patent Office, ``Subject of amendment'', 9.72 6. Contents of amendment (1-1) ``5℃ or less'' in the 4th line of page 7 of the specification has been changed to ``5℃ or less''. (1-2) Correct the contact point (al(bl
Correct J to "contact point (bl(al)". (1-3) Correct "first contact piece" in the fourth line of page 9 of the same book to "
2nd contact piece”. (1-4) Correct "5°C or lower J" in the second line of page 11 of the same book to "predetermined temperature of 5°C or lower." (2-1) Figure 1 of the attached drawings is amended as shown in the attached sheet. (2-2) Figure 4 of the attached drawings is amended as shown in the attached sheet. Figure 4Figure 4C, R

Claims (1)

[Claims] 1. A heat insulating wall with an opening for storing and taking out products on one side, and walls arranged at an appropriate distance from the inner wall of the heat insulating wall, facing each other through the opening, and when one side is an outlet, the other a partition plate that forms a passage and a storage chamber in the heat insulating wall, each having a ventilation hole serving as a suction port at both ends; a forward-reversible blower fan supported by a fan case that bisects the passage; and the fan case. and both of the vents,
two evaporators, one of which is in a cooling operation and the other is in a defrosting operation, each disposed between both the vents and both the evaporators,
two electric heaters that are energized during defrosting operation of the corresponding evaporators; and two electric heaters that are disposed within the passage and located between both the evaporators;
A low-temperature showcase comprising: a temperature detector that stops energizing the electric heaters when the air temperature in the passage reaches a predetermined temperature or higher while the two electric heaters are energized.