JPS62123277A - Method of controlling operation of freezing refrigerating open 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] [Industrial Application Field] The present invention is a refrigerated open-air refrigerator that cools the inside of the case by blocking it from outside air by forming a cold air curtain in the opening for entering and exiting products formed on the front of the case. This invention relates to a showcase operation control method.

[Conventional technology]

In order to prevent the cooling capacity from decreasing in such a refrigerated/refrigerated open showcase, two coolers should be installed and the cooling operation and operation should be performed alternately.
There is a case that is designed to perform defrosting operation. First, to explain its overall structure with reference to Figure 2, it has a showcase body ( 1) is divided into a product storage (4) and a cold air circulation duct (6) by a duct plate (3), and into a cold air circulation duct (6) and a protective air circulation duct (7) by a duct plate (5). , duct) (6) and (7), with the upper and lower ends of each as air outlet (8), (9), and suction inlet (to) (11), and the inside of the cold air circulation duct (6) is further partitioned with a partition plate (16). 2
The passageway (17a) and (17b) are divided into layers.
Coolers (18a) (7a) (17b) are installed in the respective coolers (18a) (
18b) are arranged. In the figure, (12) (13)
(14) and (15) respectively indicate the blowers installed in the cold air circulation duct (6) and the protective air circulation duct (7).
is the fan guide.

In this way, the air blower (12) (13)
0) (11) into the cold air circulation duct I-(6) and the protective air circulation duct (7), the former is cooled by the coolers (18a) (18b) and becomes cold air, and the latter is are the air outlets (8) and (9), respectively.
) is blown out to form a cold air curtain and a protective air curtain to close the opening (2).

The refrigerant circuit of the coolers (18a) (18b) will now be explained with reference to FIG. ) and liquid distillate (19c) are connected in sequence, and the condenser (19b) side of this condensation unit (19) is connected to the cooler (18a) by a refrigerant liquid pipe (20).
(18b) and the compression fi (19a) side were connected to the outlet sides of the coolers (18a) and (18b) through refrigerant gas pipes (31) to form a refrigeration cycle.

The refrigerant liquid pipe (2o) branches into three parts in the middle,
Solenoid valves (21a) (21b) near the branch points
(22) and defrosting circuit (23a) (23
b) and a cooling circuit (24), the cooling circuit (24) further branches the downstream side of the electromagnetic valve (22) into two, each of which has an expansion valve (26a) and a cooling circuit (26b).
25a) (25b) are provided to provide the defrosting circuit (23a).
Connect to the downstream side of (23b).

Further, refrigerant discharge pipes (28a) (28b) having electromagnetic valves (27a) (27b) in the middle are connected to the outlet sides of the coolers (18a) (18b), and these are connected to the refrigerant gas pipes (31). connected to. The refrigerant discharge pipe (28a)
(28b) in front of the solenoid valve (27a) (27b) and the cooling circuit (24) (7) check valve (26a)
(26b) Check valve (29a) between the CD front and the middle
) (29b) are connected by a refrigerant liquid pipe (30).

(32) in the figure indicates the solenoid valves (21a) (21b)
(22) This is a control device that controls opening and closing of (27a) and (27b).

Connect the coolers (18a) and (18b) in this way.
To perform cooling operation, the control device (32) closes the solenoid valves (21a) and (21b), and the solenoid valve (22)
(27a) If (27b) is left open, the compressor (
It is compressed to high temperature and high pressure in 19a) and then sent to a condenser (19b).
The condensed liquid refrigerant is passed from the refrigerant liquid pipe (2o) to the cooling circuit (
24) It is adiabatically expanded through the double check valves (26a) (26b) and expansion valves (25a) (25b) and enters the cooler (18a) (18b). Here, the ventilation Ia (1
2), it exchanges heat with the air sent here and evaporates into a vaporized state, leading to refrigerant discharge pipes (28a) (28b).
through the refrigerant gas pipe (31) to the condensing unit (19).
) in the accumulator (19d) and returns to the compressor (19a), thus forming a refrigeration cycle.

By the way, during the cooling operation, the cooler (18a) (18b
In order to remove this frost, the moisture contained in the air sucked into the air conditioners (18a) and (18b) adheres there as frost, which obstructs ventilation and reduces the cooling effect.
The cooling operation is stopped alternately and the defrosting operation is started. To perform this defrosting operation, for example, the cooler (18a)
To defrost the condenser (19b), open the solenoid valve (21a) and close the solenoid valves (22) (27a).
The high-temperature liquid refrigerant sent through the refrigerant liquid pipe (2o) enters one of the coolers (18a) from the defrosting circuit (23a) via the solenoid valve (21a), and is heated by the heat of this liquid refrigerant. Melt the frost adhering to the cooler (18a). The liquid refrigerant that has passed through the cooler (18a) passes through the check valve (29a), the refrigerant liquid pipe (30), and then the other cooler (18a).
8b) side through the check valve (26b) and expansion valve (25b) to enter the cooler (18b) where it performs a cooling action,
When the time set in the control device (32) has elapsed,
Both coolers (18a) and (18b) enter cooling operation.

In this way, switching between defrosting and cooling operation is performed using the solenoid valve (22).
(21a) (21b) (27a) (2
For example, when switching one of the coolers (18a) from the cooling operation to the defrosting operation as described above, conventionally the cooling circuit (24) is opened and closed as shown in the time chart of Fig. 4. Solenoid valve (22) and refrigerant discharge pipe (28)
The solenoid valve (27a) provided in a) is closed at the same time,
In addition, the solenoid valve (21a) of the defrosting circuit (23a) was opened at the same time.

[Problem that the invention seeks to solve]

Therefore, when one cooler (18a) switches to defrosting operation, liquid refrigerant for defrosting is immediately supplied to this cooler (18a) via the solenoid valve (21a).
The cooler (18a)
When the amount of frost formed is extremely large, the amount of heat contained in the liquid refrigerant sent from the refrigerant liquid pipe (20) alone may not be enough to defrost.

The purpose of the present invention is to eliminate the disadvantages of the conventional example, and when switching from dual cooling operation to defrosting operation of only one cooler,
Even when the amount of heat contained in the liquid refrigerant is not enough,
To provide an operation control method for a frozen/refrigerated open showcase that defrosts reliably.

Means for Solving Problem C] In order to achieve the above-mentioned object, the present invention provides two coolers in a cold air circulation duct provided in the showcase body, and a cooler on the refrigerant inlet side of these coolers. A cooling circuit equipped with an expansion valve, a check valve, and a solenoid valve, and a defrosting circuit equipped with a solenoid valve are formed respectively, and a refrigerant discharge circuit equipped with a solenoid valve is formed on the refrigerant outlet side of the cooler, and one of the defrost circuits is equipped with a solenoid valve. A liquid refrigerant circuit connected from the upstream side of the solenoid valve in the refrigerant discharge circuit of the cooler to the check valve in the cooling circuit of the other cooler is formed respectively, and the two coolers are alternately connected. In a refrigeration/refrigeration open cooler case that performs cooling/defrosting operation, when switching one cooler from simultaneous cooling operation to defrosting operation, before closing the solenoid valve of the cooling circuit formed on the inlet side of the cooler. The main idea is to temporarily stop the cooling operation by closing the electromagnetic valve of the refrigerant discharge circuit on the outlet side of the cooler that enters the defrosting operation.

[Effect]

According to the present invention, when switching only one cooler from a dual cooling operation to a defrosting operation, before closing the solenoid valve of the cooling circuit, the refrigerant discharge circuit on the outlet side of the cooler entering the defrosting operation is opened. Off-cycle defrosting is performed by temporarily stopping the cooling operation by closing the solenoid valve, and the cooler that enters defrosting operation is defrosted using high-temperature refrigerant after the temperature of the entire cooler is raised by this off-cycle defrosting. Start driving.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a time chart showing an embodiment of the method for controlling the operation of a frozen/refrigerated open showcase according to the present invention, and the overall structure and refrigerant circuit of the frozen/refrigerated oven sealer case used in the method of the present invention are shown in FIGS. 2 and 3. Similar to what has already been explained, inside the showcase body (1), insert the duct plate (3) (
5) Product storage (4), 2-layer aisle (17a)
It is divided into a cold air circulation duct (6) and a protective air circulation duct (7) formed by (17b), and the passage <17a
) (17b) has a cooler (18a) (18
b), and an opening (2) for entering and exiting products is provided on the front of the showcase body (1), and this is connected to the duct 1-(6).
) (7) is closed by a cold air curtain and a protective air curtain formed by blowing out from the air curtain, and a detailed explanation thereof will be omitted here.

In the operation control method for a refrigerated open showcase of the present invention, the solenoid valves (21a) (21b) (22)
(27a) and (27b) are opened and closed alternately at preset times by the control device (32), thereby allowing the cooler (
Cooling operation and defrosting operation of cooler (18a) (18b) are repeated alternately, but cooler (18a) (1
8b) From simultaneous cooling operation of two units, for example, one cooler (
When switching only 18a) to defrosting operation, as shown in the time chart of Fig. 1, the solenoid valve (22) of the cooling circuit (24) formed on the inlet side of the cooler (18b) is closed, and the solenoid valve (22) is closed. Shortly before the valve (21a) opens (for example, 3 minutes), the control circuit (32
).

When switching only the cooler (18a) from the cooling operation to the defrosting operation in this way, the cooler (18a) (1
When the solenoid valve (22) of the cooling circuit (24) formed on the inlet side of the cooling circuit (24) is not yet closed but is open and refrigerant is being supplied from the cooling circuit (24), defrosting operation is about to start. First, only the solenoid valve (27a) of the discharge circuit on the cooler (18a) side is closed. As a result, the cooler (18b) has a solenoid valve (22) and a check valve (26b) from the cooling circuit (24).
, the refrigerant is supplied via the expansion valve (25b) and cooling operation continues, while the solenoid valve (27a) of the discharge circuit closes in the other cooler (18a), so the check valve (29a)
Since the pressure is high on the downstream side, the refrigerant will not flow and the cooling operation will be interrupted. As a result, in the cooler (18a), the passage (17a)
Off-cycle defrost is performed by circulating air inside.
The temperature of the cooler (18a) increases, for example, from -10'C to O''C.

After the body temperature of the cooler (18a) rises to a certain extent in this way, the solenoid valve (22) closes and the solenoid valve (21a) opens to form a defrosting circuit, from which the cooler (18a)
A high-temperature liquid refrigerant is directly supplied to the defrosting operation.

The liquid refrigerant that has passed through the cooler (18a) during defrosting is supplied to the other cooler (18b) via the check valve (29a) and the refrigerant liquid pipe (30). Cooling operation continues.

After that, the solenoid valve (22) opens again, and the solenoid valve (21a)
is closed and the solenoid valve (27a) is opened, and the cooler (18a)
) (18b) both go into cooling operation, and then the cooler (18b) goes into defrosting operation, but the operation at this time is similar to the case of the cooler (18a), when the solenoid valve (22) is turned on. Close and slightly before the solenoid valve (21b) opens, the solenoid valve (27b)
) only closes.

Further, in the above embodiment, the case where the condensation unit (19) is installed separately from the showcase body (1) was explained as an example, but the condensation unit (19) is not limited to such an example. It goes without saying that the unit (I9) can be used with the type built in the Schiller case, and furthermore, the cooler (18a) (18b
) provided on the outlet side of the solenoid valves (27a) (27b
) and the check valves (29a) and (29b) are each 30,000 valves of III.

〔Effect of the invention〕

As described above, the method for controlling the operation of a freezer/refrigerated oven showcase of the present invention includes performing off-cycle defrosting of the cooler that enters the defrosting operation when switching only one of the coolers from the dual cooling operation to the defrosting operation. Since the temperature of the cooler can be raised in advance, even if the required amount of heat for defrosting cannot be secured from liquid refrigerant alone, defrosting can be done reliably within the specified time without causing defrosting defects. It can be defrosted.

[Brief explanation of drawings]

FIG. 1 is a time chart showing an embodiment of the operation control method for a freezer/refrigerator open showcase of the present invention, FIG. 2 is a longitudinal cross-sectional side view of the freezer/refrigerator oven showcase used in the present invention, and FIG. 3 is a refrigerant circuit diagram of the same. , FIG. 4 is a time chart showing a conventional operation control method. (1)...Open showcase body (2)...Opening (3)...Duct plate (4)...Product storage (5)...Duct plate (6)...Cold air Circulation duct (7)... Protective air circulation duct (8) (9)... Outlet (10) (11)...
Suction port (12) (13)...Blower (14) (15)...Fan guide (16) -
... Partition plate (17a) (17b) - ... Passage (18a) (18b) - Cooler (19) ... Condensing unit I-<193) ... Compressor (19b) ... Condenser ( 19C)...Liquid distillation (1
9d)...Accumulator (20)...Refrigerant liquid pipe (21a) (21b) (22) - Solenoid valve (23a) (23b) - Defrost circuit (24)
--Cooling circuit (25a) (25b) --Expansion valve (26a) (26b) --Check valve (27a)
(27b) ... Solenoid valve (28a) (28b)
... Refrigerant discharge pipe (29a) (29b) - Check valve (30) ... Refrigerant liquid pipe (31) ... Refrigerant gas pipe (32) ... Control device agent Patent attorney Masuo Oon Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] Two coolers are installed in the cold air circulation duct provided inside the showcase body, and an expansion valve and an expansion valve are installed on the refrigerant inlet side of these coolers.
A cooling circuit equipped with a check valve and a solenoid valve and a defrosting circuit equipped with a solenoid valve are formed respectively, and a refrigerant discharge circuit equipped with a solenoid valve is formed on the refrigerant outlet side of the cooler, and a defrost circuit equipped with a solenoid valve is formed on the refrigerant outlet side of the cooler. A liquid refrigerant circuit is formed from the upstream side of the solenoid valve in the refrigerant discharge circuit to a check valve in the cooling circuit of the other cooler, so that the two coolers are alternately cooled and discharged. When switching one cooler from simultaneous cooling operation to defrosting operation in a freezer/refrigeration open showcase that operates in frost mode, the defrosting operation is performed before closing the solenoid valve of the cooling circuit formed on the inlet side of the cooler. A method for controlling the operation of an open showcase for freezing and refrigerating, characterized by closing a solenoid valve of a refrigerant discharge circuit on the outlet side of a cooler that enters frost operation to temporarily stop cooling operation.