JPH07151449A - Device for defrosting cooler - Google Patents

Abstract

PURPOSE:To provide a defrosting device for a cooler in which draining can be conducted at an optimum draining time responsive to a defrosted amount of an evaporator. CONSTITUTION:When it becomes a defrosting time, defrosting means 10 is operated by defrost control means 12 to heat an evaporator 5 of a cooler located in a cold gas circulation passage 6, a latent heat changing time at the time of defrosting is measured on the basis of temperature information from temperature detecting means 11 for detecting a temperature of the evaporator 5, and a draining time is obtained in response to the measured time and a length L of the evaporator 5 in a vertical direction. After the means 10 is stopped, draining is conducted for the draining time, and then a cooling operation is restarted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a low temperature showcase and
The present invention relates to a defrosting device for a cooling device provided in a refrigerator / freezer or the like.

[0002]

2. Description of the Related Art Conventionally, in a low-temperature showcase, a refrigerator and a refrigerator, for example, Japanese Patent Publication No. 4-70546 (F.
25D21 / 08), an evaporator of a cooling device is arranged in the cold air circulation path, and the cold air heat-exchanged by this evaporator is blown into the inside of the refrigerator to cool the inside of the refrigerator. The defrosting device of the cooling device defrosts the evaporator at the timing.

Here, the defrosting device of this cooling device controls an electric heater which is a defrosting means for heating the evaporator, a temperature sensor which is a temperature detecting means for detecting the temperature of the evaporator, and a defrosting operation. Defrosting control means for Then, when the defrosting start time comes, the defrosting control means stops the cooling operation and heats the evaporator by the electric heater to defrost the evaporator, and based on the temperature information from the temperature sensor, the evaporator is defrosted. When the temperature reaches the defrosting end temperature, the electric heater is stopped and the cooling operation is restarted.

When the evaporator is defrosted, water droplets and ice blocks also drop from the evaporator on the dew tray, and the time for these to fall off and the ice blocks on the dew tray are melted and discharged. It is necessary to secure time until. Therefore, the conventional defrost control means, after stopping the electric heater,
The cooling operation is restarted after the specified draining time has elapsed, so that the dew and ice blocks from the evaporator can be reliably dropped, and the ice blocks on the dew pan should be melted and discharged. I was able to do it.

[0005]

However, in such a conventional defrosting device for a cooling device, since the draining time is a fixed time such as 5 minutes, it falls like in the summer. When the amount of dew and ice blocks increases, frost remains and re-freezing occurs due to insufficient time, and when the amount of dew and ice blocks decreases like in winter, the time becomes excessive and There is a problem in that the quality of the product is deteriorated by causing an unnecessary temperature rise.

Therefore, the present invention has been made in order to solve such a problem, and the defrosting of a cooling device capable of draining water at an optimum draining time according to the amount of frost formed on the evaporator. The purpose is to provide a device.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to defrosting means for heating an evaporator of a cooling device arranged in a cold air circulation path, temperature detecting means for detecting the temperature of the evaporator, and defrosting start. After that, the latent heat change time at the time of defrosting is measured based on the temperature information from the temperature detecting means, and after the defrosting means is stopped for the draining time obtained according to the measured time and the vertical length of the evaporator. Defrosting control means for controlling draining and then restarting the cooling operation are provided.

Further, in the present invention, the defrost control means determines the time of the cooling operation to be restarted next based on the drainage time.

Further, according to the present invention, instead of the temperature detecting means, the temperature information from the cold air temperature detecting means provided in the cold air circulating path for detecting the cool air temperature is inputted to the defrost control means and the draining time is passed. Is to be asked.

[0010]

According to the invention of claim 1, when the defrosting time comes, the defrosting control means actuates the defrosting means to heat the evaporator of the cooling device arranged in the cool air circulation path, while It is possible to measure the latent heat change time at the time of defrosting based on the temperature information from the temperature detecting means for detecting the temperature, and determine the draining time according to the measured time and the vertical length of the evaporator. Then, after the defrosting means is stopped, the water can be drained for this draining time, and then the cooling operation can be restarted.

According to the second aspect of the present invention, the defrosting control means determines the time of the cooling operation to be restarted next based on the drainage time. For example, when the drainage time is long, the amount of frost formed on the evaporator is increased. The cooling operation time can be shortened so as not to increase.

According to the third aspect of the present invention, the defrost control means is provided with a cold air circulation path and detects the cold air temperature based on the temperature information input from the cool air temperature detecting means. Can be measured, and the draining time can be determined according to this measurement time and the vertical length of the evaporator.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view of a low temperature showcase equipped with a defroster for a cooling device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a low temperature showcase body (hereinafter referred to as a body) which is formed by a heat insulating wall 1a and has a front surface opened. A commodity storage chamber 2 formed in the body 1 has a plurality of shelves. 3 are arranged vertically.

Further, the back of the product storage chamber 2 is formed by two partition plates 4 and 4 arranged at a predetermined interval, and an evaporator 5 of a cooling device is arranged. A cold air passage 6, which is a cold air circulation path, is formed. Then, the cool air from the evaporator 5 is blown out from the cool air outlet 7 provided at the front end of the top of the product storage chamber 2 to cool the inside of the product storage chamber 2 and, as shown by the arrow in FIG. The main body 1 is sucked into the cold air suction port 8 provided at the bottom front end of the storage chamber 2.
An air curtain is formed to cover the front opening 9.

By the way, an electric heater 10 for heating the evaporator 5 is provided in the vicinity of the evaporator 5, and a temperature detecting means for detecting the temperature of the evaporator 5 is provided at a predetermined position on the surface of the evaporator 5. The defrost sensor 11 is attached. Further, at a predetermined position of the main body 1, a controller 12, which is a defrost control means, is arranged above the tip of the main body 1 in this embodiment.

Here, the controller 12 operates the electric heater 10 to heat the evaporator 5 at the defrosting start time, and based on the temperature information from the defrosting sensor 11 input at a predetermined timing. During defrosting, the latent heat change time is measured, and the draining time is obtained according to the measured time. Note that this latent heat change time depends on the evaporator 5
When the amount of frost formed on the evaporator 5 is large, the length becomes long, and when the amount of frost formed on the evaporator 5 is small, the length becomes short.

By the way, in the controller 12, a table showing the relationship between the optimum drainage time and the measurement time previously obtained by experiments or the like so that the optimum drainage time can be obtained from the measurement time (shown later in FIG. 3). Is stored, and the controller 12 can obtain the optimum draining time according to the latent heat change time, that is, according to the amount of frost formed on the evaporator 5 from the measurement time and the table.

Since the surface temperature of the evaporator 5 slightly changes during defrosting, in this embodiment, it is not the time when the surface temperature of the evaporator 5 is 0 ° C. , The surface temperature of the evaporator 5 is from -0.5 ° C to + 0.5 ° C.
The temperature change time within the corrected temperature (ΔT) is calculated as follows.

Further, the length L of the evaporator 5 in the vertical direction has an influence on the falling time of dew and ice blocks, and therefore the length L of the evaporator 5 must be taken into consideration in order to obtain this draining time. Therefore, the controller 12 is configured to store a table corresponding to the length L of the evaporator 5, respectively. As a result, even when the evaporators 5 having different lengths are attached, it is possible to obtain the draining time depending on the length of the evaporator 5.

On the other hand, the controller 12 includes the evaporator 5
When the temperature reaches a predetermined defrosting end temperature, for example, 10 ° C., the electric heater 10 is stopped, the water is drained for the required draining time, and then the cooling operation is restarted. As a result, the cooling operation and the defrosting operation are repeatedly performed.

Next, the water-draining time setting operation of the defroster of the cooling device thus constructed will be described with reference to the surface temperature change curve of the evaporator shown in FIG. In the figure, the vertical axis represents the temperature of the evaporator surface and the horizontal axis represents time.

At the defrosting start time T1, the controller 12 operates the electric heater 10 to heat the evaporator 5,
This causes the temperature of the evaporator 5 to rise. The temperature information of the evaporator 5 at this time is input from the defrost sensor 11 to the controller 12 at a predetermined timing.

The surface temperature of the evaporator 5 is -0.5 ° C.
Then, the controller 12 starts measuring the latent heat change time, continues the measurement until the surface temperature of the evaporator 5 reaches + 0.5 ° C., and obtains the latent heat change time. From the measured time T2,
The draining time T3 is calculated based on the table shown in FIG. 3 corresponding to the length L of the evaporator 5 which is input in advance. Here, for example, when the measurement time T2 is 6 minutes, the controller 12 sets the draining time T3 to 5 minutes from the table of FIG.

After that, when the temperature of the evaporator 5 reaches 10 ° C., the controller 12 stops the electric heater 10 and then
The draining time T3 thus obtained, that is, draining is performed for 5 minutes, and then the cooling operation is restarted. In addition,
In FIG. 2, T4 is the energization time of the electric heater 10, and the sum of the heater energization time T4 and the drainage time T3 is the defrosting operation time T5.

As described above, the controller 12 measures the latent heat change time during defrosting based on the temperature information from the defrost sensor 11, and determines the measured time T2 and the length L of the evaporator 5 in the vertical direction. The time T3 for draining can be obtained.

By the way, in the above description, the controller 12 has been described as obtaining the draining time T3 based on the measurement time T2 and the length L of the evaporator 5, but the present invention is not limited to this, and the draining time is not limited to this. Time T3 is evaporator 5
Since it is proportional to the amount of frost formed on the
It is also possible to determine the time T6 (see FIG. 2) of the cooling operation to be restarted next based on the above.

That is, when the amount of frost is large and the draining time T3 is long, the cooling operation time T6 is shortened so that the frost does not adhere to the evaporator 5, and the amount of frost is small and the draining time T3 is small.
If is short, the cooling operation time T6 is made long. This makes it possible to set the cooling operation time T6 according to the amount of frost formed on the evaporator 5.

In order to obtain the cooling operation time T6 to be restarted next based on the water draining time T3, the water draining time T3 and the amount of dew or ice blocks dropped and discharged at this water draining time T3 are generated. The cooling operation time T6 is obtained in advance by experiments and the like, and the table shown in FIG. 4 showing the relationship is stored in the controller 12, and the water draining time T3 is obtained as described above, and then the water draining time T3 and this table are used. I try to ask.

The table of FIG. 4 shows that the draining time T3
The measurement time T2 is used instead of. Then, for example, when the measurement time T2 is 6 minutes, the next cooling operation time T6 can be set to 6 hours.

On the other hand, in the above description, the defrost sensor 11 is attached to the surface of the evaporator 5 to measure the latent heat change time from the surface temperature of the evaporator 5, but the present invention has been described. The invention is not limited to this, and as shown in FIG. 1, a discharge temperature sensor 13 for detecting the cool air temperature may be provided in the cool air passage 6 in the vicinity of the cool air outlet 7.

Here, the cold air temperature draws almost the same temperature change curve as the surface temperature change curve of the evaporator 5 as shown by the broken line in FIG. If the temperature of the cool air discharged from 5 is detected, even if the surface temperature of the evaporator 5 is not directly detected, the latent heat change time during defrosting and the temperature of the evaporator 5 are 10
It can also detect that the temperature has reached ℃. By providing the discharge temperature sensor 13 at such a position, replacement and repair work can be easily performed when the discharge temperature sensor 13 fails.

[0033]

As described above, according to the present invention, the latent heat change time at the time of defrosting is measured, and the draining time is determined according to the measured time and the vertical length of the evaporator. It is possible to perform draining at an optimum draining time according to the amount of frost formed on the evaporator. Further, by determining the time of the cooling operation to be restarted next based on the drainage time, the cooling operation time can be set according to the frost formation amount of the evaporator. Furthermore, if the measurement of the latent heat change time at the time of defrosting is performed by the cool air temperature detecting means provided in the cool air circulation path, the work such as replacement of the cool air temperature detecting means can be easily performed.

[Brief description of drawings]

FIG. 1 is a side sectional view of a low temperature showcase including a dehumidifying device for a cooling device according to an embodiment of the present invention.

FIG. 2 is a surface temperature change curve of an evaporator.

FIG. 3 is a table showing the relationship between the latent heat change time measurement time and the drainage time.

FIG. 4 is a table showing the relationship between the measured time and the next cooling operation time.

[Explanation of symbols]

 5 evaporator 6 cold air passage 10 electric heater 11 defrost sensor 12 controller 13 discharge temperature sensor

Claims (3)

[Claims] 1. A defrosting means for heating an evaporator of a cooling device arranged in a cold air circulation path, a temperature detecting means for detecting a temperature of the evaporator, and a defrosting means for detecting a temperature from the temperature detecting means after starting defrosting. Measure the latent heat change time at the time of defrosting based on the temperature information, and let the water drainer perform after the defrosting means is stopped for the water draining time required according to this measurement time and the vertical length of the evaporator, and then perform the cooling operation. A defrosting device for an evaporator, comprising: a defrosting control unit that controls to restart the operation. 2. The defrosting device for an evaporator according to claim 1, wherein the defrosting control means determines a time for the cooling operation to be restarted next based on the draining time. 3. Instead of the temperature detecting means, the temperature information from the cold air temperature detecting means provided in the cold air circulating path for detecting the cool air temperature is input to the defrost control means to obtain the draining time. The method according to claim 1, wherein
The evaporator defrosting device described.