JPH02251078A - Defrosting of cold storage showcase equipped with front door - Google Patents

Abstract

PURPOSE:To permit defrosting under a condition that a cooler is stabilized uniformly by a method wherein a heater is arranged in a cold air circulating passage while the defrosting is effected by conducting the heater and operating at least one set of fan while stopping at least one set of the other fan. CONSTITUTION:Upon the cooling operation of a cold storage showcase, the conduction of a sheath heater 13 is intercepted and a cooler 11 as well as fans 12A, 12B are operated to cool the inside 6 of the case. Upon defrosting, the power source of the fans 12A, 12B are retained continuously in the condition of ON and the operation of the cooler 11 is stopped while the sheath heater 13 is conducted. In this case, a contact 15a is closed by putting a relay 15 ON and another contact 15b is opened whereby the fan 12B is stopped. Under this condition, hot air, heated by the sheath heater 13, passes through the cooler 11 while defrosting the left half of the cooler 11 and flows reversely through the right half of the cooler 11, in which the fan 12B is being stopped, then, the air is circulated into the suction side of the fun 12A.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention has a main body case having a U-shaped cross section and a door at the front opening, and a cooler and a plurality of fans in a cold air circulation path formed inside the main body case. In a refrigerated showcase with a front door that uses a fan to circulate the air inside the refrigerator and cool the interior of the refrigerator formed inside the main case, a defrosting system removes frost formed during cooling operation. Regarding the method.

[Conventional technology]

As this type of refrigerated showcase, the one shown in FIG. 3 is known. In the figure, the refrigerated showcase consists of a main body case 1 with a U-shaped cross section and an open front, an outer box 2 and an inner box 3 made of heat insulating walls, and a cold air circulation path between the outer box 2 and the inner box 3. 4 is formed. The front opening of the outer box 2 is provided with a door 5 fitted with a large glass in the center, and a refrigerator interior 6 is formed inside the inner box 3. Reference numeral 7 denotes a plurality of shelves that partition the interior 6 into upper and lower stages. A cooler 11 extending along the longitudinal direction of the outer box 2, a plurality of fans 12 arranged in parallel at appropriate corners along the longitudinal direction, and a sheathed heater 13 are disposed at the bottom of the cold air circulation path 4. be done.

In the refrigerated showcase, a large number of products are stored and displayed on the shelves 7. Thus, the cooler 11 and the fan 12 are operated, and the fan 12 sucks the air inside the refrigerator into the cold air circulation path 4 from the suction port 4a, where it is cooled by the cooler 11 to become cold air, and then from the air outlet 4b equipped with an air conditioning fluid. The air is blown out to form a cold air curtain on the front surface of the refrigerator, cool the interior 6 of the refrigerator, and circulate. The cold air refrigerates the products in the warehouse to a predetermined temperature.

Since continuation of the above-mentioned cooling operation causes frost to form on the cooler 11 and decreases the cooling capacity, the refrigerated showcase is periodically operated for defrosting. In this defrosting operation, the operation of the cooler 11 and the fan 12 is stopped, and the sheathed heater 13 is energized. The heated air heated by the sheathed heater 13 becomes an upward air current, washes the cooler 11, and melts and removes frost. When the fan 12 is operated during this defrosting, the heated air is sent into the warehouse 6 with residual heat, warming the products in the warehouse, and the water vapor generated by the defrosting of the cooler 11 is also discharged into the warehouse. This water vapor is sent into the interior 6 and adheres to the products in the warehouse and condenses, causing problems such as frost formation on the surfaces of the products when the cooling operation is restarted. Therefore, conventionally, the fan 12 is not operated during defrosting.

[Problem to be solved by the invention]

By the way, in the conventional defrosting method, the heated air is transferred to the cooler 1 depending on the temperature inside the refrigerator at that time and the heat capacity of the products inside the refrigerator.
After passing through 1, the air flows in the -E direction through the cold air circulation path 4 at the rear of the refrigerator, or flows upward through the front part of the refrigerator through the suction port 4a. In the former case, the cold air flowing into the cold air circulation path 4 from the suction port 4a prevents the front part of the cooler 11 from being heated, and the cooler 11
The progress of defrosting is extremely unbalanced between the front and rear parts. In the latter case, defrosting of the rear part of the cooler 11 is delayed. As described above, in the conventional method, the defrosting of the cooler 11 is affected by the internal condition of the refrigerator and is not performed uniformly for each part of the cooler 11, and this instability of defrosting makes it difficult to detect the end of defrosting. It was causing problems such as making it difficult.

An object of the present invention is to provide a defrosting method that can uniformly and stably defrost a cooler in a refrigerated showcase with a front door.

[Means to solve the problem]

In order to achieve the above object, according to the present invention, a cold air circulation path is formed inside the main case having a U-shaped cross section and a door at the front opening, and a refrigerator interior is formed inside the main case, and the cold air circulation path is formed inside the main case. A refrigerated showcase with a front door is provided with a cooler and a plurality of fans installed in parallel, and the fan circulates air inside the refrigerator through the cooler to cool the interior of the refrigerator. The heater is energized, and at least one of the fans is operated and at least one of the fans is stopped for defrosting.

[Effect]

The fan forces heated air into the cooler, and the heated air circulates through the cooler in the opposite direction toward the fan when it is stopped. Therefore, heated defrosting air that is heated by the sheathed heater and flows in a fixed direction while flushing the cooler is always obtained, and defrosting is performed uniformly and stably.

[Embodiment] FIGS. 1 and 2 show an embodiment according to the present invention, and parts common or identical to those in FIG. 3 are designated by the same reference numerals.

1 and 2, two fans 1 on the left and right sides are installed at the bottom of the cold air circulation path 4 formed in the main body case 1.
2A and a fan 12B are provided.

The electric circuit of the sheathed heater 13 and the fans 12A and 12B is as shown in FIG.
1 contact (A contact) of relay 15 for each of the 3 electric circuits
5a, and a contact 15b serving as a b contact of this relay 15 is provided in the electric circuit of the fan 5B.

In the above configuration, in the refrigerated showcase, during cooling operation, power is cut off to the sheathed heater 13 and the cooler 11 is turned off.
Then, the fans 13A and 13B are operated, and the interior 6 of the refrigerator is cooled in the same manner as before.

During defrosting, the power to fans 12A and 12B is kept on.
N is maintained, the operation of the cooler 11 is stopped, and the sheathed heater 13 is energized. At this time, relay 15 is turned on.
As a result, the contact 15a closes and the contact 15b opens to stop the fan 13B. However, sheathed heater 1
As shown by the arrow, the heated air heated by the fan 128 passes through the cooler 11 while defrosting the left half of the cooler 11, and then flows in the opposite direction through the right half where the fan 12B stops, and then flows in the opposite direction to the fan 12A. Circulate toward the suction side of the In this way, the flow of heated air is constant, and the heated air washes over the entire cooler 11, regardless of the heat capacity of the stored products in the refrigerator interior 6. Therefore, each part of the cooler 11 is defrosted uniformly and always stably. Additionally, by installing sensors in specific locations, it is possible to reliably detect when it is time to defrost.

〔Effect of the invention〕

According to this invention, a cold air circulation path is formed inside the main case having a U-shaped cross section and a door at the front opening, and a refrigerator interior is formed inside the main case, and a cooler and a cooler are installed in parallel in the cold air circulation path. In a refrigerated showcase with a front door, which is equipped with a plurality of fans and which cools the inside of the refrigerator by circulating the air inside the refrigerator through the cooler, a heater is disposed in the cold air circulation path, and the heater is energized. In addition, since at least one of the fans is operated and at least one of the fans is stopped for defrosting, the heated air for defrosting is always circulated in a fixed direction, and each part of the cooler is cooled. Average
Warm to. Therefore, defrosting can be performed stably in each part regardless of the heat capacity inside the refrigerator. This also makes it possible to correctly detect the end time of defrosting.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a main part of a refrigerated showcase for explaining a defrosting method according to an embodiment of the present invention, Fig. 2 is an electric circuit diagram, and Fig. 3 is a refrigerated showcase to which the present invention is applied. FIG. 1...Main body case, 4...Cold air circulation path, 5...Door, 6...Inside the refrigerator, 11...Cooler, 12.12A, 1
2B...Fan, 13...Sheathed heater.

Claims (1)

[Claims] 1) A cold air circulation path is formed inside the main case with a U-shaped cross section and a door at the front opening, and a refrigerator interior is formed inside the main case, and a cooler and a plurality of fans installed in parallel are installed in the cold air circulation path. In the refrigerated showcase with a front door that cools the inside of the refrigerator by circulating the air inside the refrigerator through the cooler using the fan, a heater is disposed in the cold air circulation path, the heater is energized, and at least A method for defrosting a refrigerated showcase with a front door, characterized in that defrosting is performed by operating one of the fans and stopping at least one of the fans.