JPH0526462Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an improvement of a refrigerated open shower case in which defrosting is performed using hot gas and a duct heater.

<Prior Art> Fig. 4 is a vertical cross-sectional view showing an example of a conventional refrigerated/freezer open case.
1 is a case main body having an opening 2 on the front for loading and unloading products, and the interior is divided by duct plates 3 and 5 into a product storage 4, a cold air circulation duct 6, and a protective air circulation duct 7. A blower 12 and a cooler 14 are sequentially disposed within the cold air circulation duct 6, while a blower 13 is disposed within the protective air circulation duct 7.

In addition, the cold air circulation duct 6 and the protective air circulation duct 7 are provided with blow-off ports 8 and 9 located front and rear above the opening 2, and air inlet ports 8 and 9 located front and rear below the opening 2. Ports 10 and 11 are formed.

Further, a duct heater 15 is disposed downstream of the suction port 11 of the protective air circulation duct 7. still,
Reference numeral 16 denotes a heating preventer for detecting the completion of defrosting, which is attached to the refrigerant pipe on the outlet side of the cooler 14.

In the refrigerated open-air storage case configured as described above, the blowers 12 and 13 are operated to circulate air, and cold air and protective air are blown out from the air outlets 8 and 9 cooled by the cooler 14 to form an air curtain in the opening 2. The inside of the product storage 4 is maintained at a low temperature. In other words, the cold air blown out from the outlet 8 forms an air curtain in the opening 2, where it entrains some of the hot and humid air from outside, rises in temperature, and is sucked into the inlet 10, where it is cooled by the blower 12. The liquid is fed into the vessel 14, cooled, and then blown out from the outlet 8 again. In this way, the inside of the product storage 4 is maintained at a low temperature, but if the operation continues for a certain period of time, the moisture in the air sucked into the cold air circulation duct 6 and circulated is cooled by the cooler 14 and condenses, causing frost. As a result, frost forms on the surface of the cooler 14, reducing the cooling efficiency of the cooler 14. For this reason, it is necessary to defrost. Defrosting is
This is done by directly introducing high-temperature, high-pressure refrigerant gas, that is, hot gas, discharged from the compressor at regular intervals, three to six times a day, into the cooler 14, and using the heat to heat and melt the frost. There is. At this time, the blower 12 in the cold air circulation duct 6 is stopped to prevent the temperature of the product storage 4 from rising.

The amount of frost that forms in the cooler 14 varies depending on the surrounding conditions in which the refrigerated open case is used, but in order to always complete defrosting in the shortest possible time,
A heating preventer 16 for detecting the completion of defrosting is attached to the refrigerant pipe on the outlet side of the cooler 14, and when the pipe temperature reaches a set temperature, the defrosting operation is terminated as the defrosting is completed. In winter, when the temperature and absolute temperature of the surrounding air decreases, the amount of frost on the cooler 14 decreases, so during defrosting, the temperature of the temperature sensor 16 rises in a short time and the defrosting of the cooler 14 is completed. However, the frost that forms on the duct plate 5 forming the cooling circulation duct 6 is difficult to melt because the temperature of the circulating air in the protective air circulation duct 7 also decreases as the ambient air temperature decreases, and for this reason, the frost formed on the duct plate 5 forming the cooling circulation duct 6 is difficult to melt. The temperature of the circulating air in the protective duct 7 is increased by the duct plate 5.
It is designed to melt the frost.

FIG. 5 is a time chart of the above operation. Defrosting of the cooler 14 is started at regular intervals. At this time, the blower 12 is stopped and the hot gas solenoid valve is opened, so that hot gas is supplied to the cooler 14. flows. As a result, when the frost melts and the temperature of the cooler 14 rises to reach the set temperature of the overheat preventer 16, defrosting is completed, the blower 12 starts operating, and the solenoid valve closes to return to cooling operation.

<Problems to be solved by the invention> In conventional open-air refrigerated storage cases, the frost that forms on the duct board during defrosting in winter is completely defrosted, so a duct heater is installed in the protective air circulation duct. The same heater is always energized to heat the protective air.

Therefore, the duct heater is energized even when heating is not required, such as during cooling operation or during defrosting in the summer, which results in wasted energy consumption, which goes against energy savings and increases operating costs. There was a problem of growth.

<Means for Solving the Problems> In order to solve the above-mentioned problems, the present invention has a cold air circulation duct in which a cooler is disposed inside the case body and a protective air circulation duct in which a duct heater is disposed. The cooling air and protective air are blown out from the upper outlet of each duct to form an air curtain at the case opening, thereby maintaining the inside of the refrigerator at a low temperature and introducing hot gas to remove frost that has formed on the cooler. In the refrigeration/refrigeration open shower case, the cooler is provided with a first temperature sensor for detecting the completion of defrosting, and either the protective air circulation duct or the cold air circulation duct is provided with a second temperature sensor for detecting the completion of defrosting. A temperature sensor for detecting the completion of defrosting is provided, and at the time of defrosting, hot gas is supplied to the cooler and the duct heater is energized to perform defrosting operation, and the first temperature sensor for detecting the completion of defrosting reaches a set temperature. When the temperature reaches the set temperature, the supply of hot gas is stopped, and when the second defrosting completion detection temperature sensor reaches the set temperature, the duct heater is cut off, and the duct heater is energized only when heating is required. It is characterized by the fact that it is made in a similar manner.

<Operation> As described above, the first temperature sensor for detecting the completion of defrosting and the second temperature sensor for detecting the completion of defrosting are provided, and the supply of hot gas is stopped by the first temperature sensor for detecting the completion of defrosting, Since the second defrost detection temperature sensor cuts off the power to the duct heater that is energized at the same time as defrosting starts, the duct heater is energized only during the period when it requires heating during defrosting. Become.

In other words, there is almost no frost on the ducts, unlike during cooling operation or defrosting operation in the summer, and even when defrosting operation begins, the temperature of the air circulating through the protective air circulation duct and the cold air circulation duct is sufficiently high. When heating by the duct heater that immediately reaches the set temperature of the second defrosting completion detection temperature sensor is not required, the duct heater is not energized. Also, in winter, when the ambient temperature is low and the amount of frost on the cooler is small, defrosting can be done relatively quickly, but when heating with a duct heater is necessary, when the frost that has formed on the duct is difficult to melt,
Even after the supply of hot gas is stopped, electricity is supplied to continue heating until the set temperature of the second defrosting completion detection temperature sensor is reached, and sufficient heating is performed only when truly necessary.

<Example> An example of the present invention will be described below based on FIGS. 1 to 3.

FIG. 1 is a vertical cross-sectional view of a refrigerated/refrigerated open case according to the present invention. In the figure, numerals 1 to 16 are the same as those of the conventional case shown in FIG. 4, and the explanation thereof will be omitted.

In this embodiment, a GA temperature sensor 17 is installed at the upper part near the air outlet 9 in the protective air circulation duct 7 to detect the temperature of the protective air circulating in the protective air circulation duct 7. When the temperature of the protective air is higher than the GA
When the temperature of the temperature sensor 17 reaches the set temperature, the power supply to the duct heater 15 is cut off at the same time as the defrosting starts.

That is, in this embodiment, the hot gas discharged from the compressor is supplied to the defrosting cooler 14, and the duct heater 15 is energized to heat the cooler 14 and the protective air, so that the frost melts and the overheat preventer 16 is activated. When the set temperature is reached, hot gas supply to the cooler 14 is stopped, and when the GA temperature sensor 17 reaches the set temperature, the duct heater 15 is cut off.

FIG. 2 is a time chart showing the operation of the frozen/refrigerated open case with the above configuration. During the cooling operation, the blowers 12 and 13 are operated to blow air into the cold air circulation duct 6 from the suction ports 10 and 11. Circulating air is cooled by the cooler 14 and blown out from the outlets 8 and 9 to form a cold air curtain in the opening 2 and keep the inside of the product storage 4 at a low temperature.

If such cold air operation is continued, cooler 1
4, the cooling capacity decreases due to frost formation, so after a certain period of cooling operation, the blower 12 is stopped, the hot gas solenoid valve is opened, hot gas discharged from the compressor is introduced into the cooler 14, and the duct heater 15 is energized. and start defrosting operation.

The cooler 14 is heated by the supply of hot gas, and when the frost melts, the temperature of the cooler 14 rises, and when it reaches the set temperature of the desuperheater 16, the desuperheater 1
6 is turned ON, the hot gas solenoid valve is closed, and the supply of hot gas is stopped.

However, when the ambient temperature is low and the temperature of the circulating air in the protective air circulation duct 7 is difficult to rise, such as in winter, even after the desuperheater 16 is turned on and the supply of hot gas is stopped, the temperature of the circulating air in the protective air circulation duct 7 is The duct heater 15 is energized and continues heating until the circulating air temperature reaches the set temperature of the GA temperature sensor 17. That is, complete defrosting is achieved by continuing heating by the duct heater 15 until the frost formed on the duct plate 5 melts and the temperature of the circulating air in the protective air circulation duct 7 rises.

On the other hand, in the summer, the temperature of the air circulating through the protective air circulation duct 7 is sufficiently high, so that almost no frost forms on the duct 5. Therefore, even while hot gas is being supplied to the defrosting cooler 14, the protective air circulation duct 7
The temperature of the circulating air is measured by the GA temperature sensor 17.
Since it is turned on, as shown in Figure 3, even if the duct heater 15 is once energized at the start of defrosting, it is immediately cut off, heating by the duct heater 15 is not performed, and when the overheating preventer 16 is turned on, hot gas is supplied. is stopped and defrosting operation is completed.

In this way, even during defrosting, the necessary and sufficient amount of heat can be supplied only when heating is required, and unnecessary energy consumption can be eliminated, so it is possible to reduce operating costs by saving energy.

In the above embodiment, an example was explained in which the GA temperature sensor 17 was arranged at the upper part near the outlet 9 of the protective air circulation duct 7.
It may be installed in the middle of the cold air circulation duct 6 or at the upper part near the outlet 8 of the cold air circulation duct 6, and the same effect as in the above embodiment can also be obtained.

<Effects of the invention> As is clear from the above explanation, according to the invention,
Power is applied to the duct heater only when heating by the duct heater is truly required, such as during defrosting in winter.
Since the power to the duct heater can be cut off when heating by the duct heater is not required, such as during cooling operation or defrosting in the summer, defrosting can be performed reliably, and at the same time, there is no wasted energy consumption, reducing operating costs. We can provide cheap and economical frozen and refrigerated open storage cases.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of the open freezer case according to the present invention, Figs. 2 and 3 are time charts of the open case in winter and summer, and Fig. 4 is a conventional open case for the refrigerated freezer. FIG. 5, which is a longitudinal sectional view of the show case, is a time chart during its operation. In the figure, 1 is the case body, 2 is the opening, 3, 5
is a duct plate, 4 is a product storage, 6 is a cold air circulation duct, 7 is a protective air circulation duct, 8 and 9 are air outlets,
10, 11 are suction ports, 12, 13 are blowers, 14
15 is a duct heater, 16 is an overheat protector, and 17 is a GA temperature sensor.

Claims (1)

[Scope of Claim for Utility Model Registration] A cold air circulation duct in which a cooler is disposed inside the case body and a protective air circulation duct in which a duct heater is disposed are arranged in front and behind each other, and each duct has an upper air outlet. A refrigerator/refrigerator opener that blows out cold air and protective air to form an air curtain at the case opening to keep the inside of the refrigerator at a low temperature, and defrosts the frost that has formed on the cooler by introducing hot gas. In the case, the cooler is provided with a first temperature sensor for detecting the completion of defrosting, and either the protective air circulation duct or the cold air circulation duct is provided with a second temperature sensor for detecting the completion of defrosting. At the same time, hot gas is supplied to the cooler and electricity is applied to the duct heater, and when the first temperature sensor for detecting the completion of defrosting reaches the set temperature, the supply of hot gas is stopped and the second defrosting A refrigerator/freezer open case characterized in that when a temperature sensor for detecting completion reaches a set temperature, power to the duct heater is cut off.