JPH0584434B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the operation of a refrigerated open show case for displaying and selling products that require refrigeration.

[Conventional technology]

FIG. 6 shows a vertical cross-sectional view of a conventional refrigerated open show case. The front side of a main body 1 formed by a heat insulating wall 3 is an opening 2 for entering and exiting products, and the inside of the main body 1 is partitioned with a duct plate 6 to display products. It is divided into a chamber 10 and a cold air circulation path 7.

A blower 9 and a cooler 8 are disposed in this cold air circulation passage 7, and each end of the cold air circulation passage 7 serves as an air outlet 4 and an inlet 5, and is connected to the upper end of the front opening 2. Face the bottom edge. Further, reference numeral 11 in the figure indicates a product shelf provided in multiple stages in the product display room 10.

In the refrigerated open case with such a configuration, the cold air sucked in from the suction port 5 by the blower 9 is cooled by the cooler 8, and is blown out from the air outlet 4 through the cold air circulation path 7, and an air curtain is formed in the front opening 2. At the same time, the interior of the product display room 10 is cooled to a desired temperature, and the air is sucked in through the suction port 5 again, and this circulation is repeated. In this case, the air is sucked in by the blower 9 and sent to the cooler 8. The amount of is always constant.

By the way, even if the air volume sent by the blower 9 is constant, the air volume blown out from the air outlet 4 changes depending on the outside temperature and the elapsed operation time.This relationship is as shown in Fig. 4 when the initial air volume Wmax is constant. As shown in the characteristic curve diagram, the blown air volume decreases as the operating time T ₁ elapses, and the degree of the decrease increases as the outside air temperature increases. Here, to explain the reason why the amount of air blown decreases with the elapsed operating time, the air blown to the cooler 8 by the blower 9 as described above is cooled by the cooler 8 and becomes cold air, but at this time, the air becomes colder than the dew point. Then, the moisture in the air becomes frost and adheres to the cooler 8. This frosting phenomenon occurs at any time during the cooling operation, and the amount of frosting on the cooler 8 gradually increases. When the amount of frost increases in this way, the airflow resistance of the air passing through the cooler 8 increases, and as a result, the airflow volume blown from the cooler 8 gradually decreases over time. Furthermore, when the relative humidity is constant, the higher the temperature, the greater the amount of moisture contained in the air, and therefore, the higher the outside temperature is, the greater the degree of reduction in the blowout air volume.

Furthermore, the relationship between the blowout air volume, the internal temperature variation value, the required refrigerating power of the case, and the outside air temperature is
As shown in the characteristic curve diagram in the figure, as the blowout air volume W increases, the required refrigerating capacity Q increases,
The internal temperature variation value ΔT becomes smaller. Also,
When the blowout air volume is constant, as the outside temperature decreases, both the required refrigerating capacity Q and the internal temperature variation value ΔT decrease.

[Problem to be solved by the invention]

In order to maintain the freshness of stored products in the product display room, it is desirable to always maintain the internal temperature variation value ΔT below a certain value.

However, in the past, since the amount of air blown by the fan was constant, for example, in order to set the variation value of the internal temperature to a predetermined value ΔT 25 or less required to maintain the freshness of the product, it was necessary to set the variation value of the temperature inside the refrigerator to a predetermined value ΔT ₂₅ or less required to maintain the freshness of the product. In order to obtain the predetermined variation value ΔT ₂₅ even under the conditions of
It is necessary to set the air volume to W ₁ .

Therefore, even in the middle of spring, autumn and winter when the outside air temperature is lower than in summer, the air volume is operated at the value of W ₁ , and during this period, the internal temperature variation value ΔT is kept at the predetermined value of ΔT ₂₀ and ΔT ₁₅ . It becomes much smaller than ΔT ₂₅ , and the internal temperature variation value becomes smaller than necessary.

As a result, the conditions inside the refrigerator are more sufficient than those obtained under the minimum internal temperature variation value ΔT ₂₅ required to maintain product freshness, and the extra capacity of the blower and cooler is consumed accordingly. , which goes against energy-saving measures.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
Operation control of refrigerated open case that keeps the internal temperature variation at the minimum required value in response to the outside temperature, maintains the freshness of products, and also helps save energy without consuming excess energy. The purpose is to provide a method.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention divides the interior of the main body, which has an opening for entering and exiting products on the front surface, into a product display room and a cold air circulation path in which a blower and a cooler are installed. In a refrigerated open show case in which the cold air circulation air path ends are formed at the air outlet and suction port facing the upper and lower ends of the product inlet/outlet opening and the opening surfaces are closed with a cold air curtain, a blowout air volume sensor is provided to perform cooling operation. The gist is to calculate the outside air temperature from the airflow volume detected by the airflow sensor after a predetermined time has elapsed after the start, and then adjust the airflow volume thereafter so that a predetermined internal temperature variation value is obtained under this outside air temperature. That is.

[Effect]

According to the present invention, based on the fact that the amount of air blown from the outlet decreases as the operating time elapses and as the outside temperature increases, After half the time until the start of the next defrosting operation has elapsed, the outside air temperature is calculated from the blowout air volume detected by the blowout airflow sensor, and the minimum necessary internal temperature variation value is calculated from this outside air temperature. The amount of blowing air necessary to obtain the desired amount of air is calculated, and the cooling operation is performed based on this amount of air. Therefore, the temperature inside the refrigerator is always set to the minimum necessary internal temperature variation value, so the freshness of the products in the refrigerator can be maintained without wasting energy.

〔Example〕

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

Fig. 1 is a flowchart showing an embodiment of the method for controlling the operation of a refrigerated open shed case according to the present invention, and Fig. 2 is a longitudinal sectional side view of the refrigerated open shed case used in this embodiment. The overall configuration will be explained.

In FIG. 2, the same components as those of the conventional example already explained with reference to FIG. 6 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

The basic structure of the refrigerated open-air case is the same as the conventional one, but the one used in the method of the present invention is equipped with a blowout air volume sensor 12 at the blower outlet 4 to measure the amount of cold air blown out from the blower outlet 4. An air volume variable device 14 using inverter control, phase control, etc. for adjusting the air blower was connected to the air blower 9 disposed in the air circulation air path 7.

Furthermore, an internal temperature variation value setting device 13 for setting the internal temperature variation value linearly as shown in FIG. 3 is provided near the outside of the air outlet 4. The internal temperature variation value setting device 13 is not limited to one that can set the internal temperature variation value linearly, but can also be set in two stages or three stages using an on-off switch, etc.
It is also possible to use a step-like setting with more than one stage.

Further, a control device 15 using a microcomputer or the like is provided, and output signals from the blowout air volume sensor 12 and the internal temperature variation value setting device 13 are introduced into the control device 15, and the control signals from the control device 15 are transmitted to the air flow rate. It was introduced into the variable device 14.

Next, the operation will be explained.

Cold air sucked in from the suction port 5 by the blower 9 is cooled by the cooler 8 as in the conventional case, and is blown out from the air outlet 4 through the cold air circulation air path 7 to form a cold air curtain in the front opening 2. At the same time,
The inside of the product display room 10 is cooled, and the air is sucked in through the suction port 5 again, and this circulation is repeated.

In this operating operation, the first method is to always set the variation value of the internal temperature to the minimum necessary value that can maintain the freshness of the stored products in the product display room 10.
The flowchart shown in the figure will be explained.

At the initial stage of operation, the outside temperature is, for example, 25℃.
In order to obtain the minimum internal temperature variation necessary to maintain product freshness even under high summer conditions,
The internal temperature variation value is set to ΔTmax, and the air volume W is also set to the maximum air volume Wmax.

Cooling operation starts with this setting value, and the operation time T ₁
(T ₁ = 1~3Hr), the airflow sensor 1
2, the blowout air volume W _T1 is detected, and this blowout air volume W _T1
is output to the control device 15.

Based on this detected value W _T1 , the control device 15 calculates the current outside air temperature Tout based on the relationship between the elapsed operation time, the airflow volume, and the outside air temperature shown in FIG. 4 (Tout=f(W, T ₁ )).

Based on the outside air temperature Tout obtained in this way,
Based on the relational characteristics of airflow volume, outside air temperature, internal temperature variation, and required refrigerating capacity shown in Figure 5, the minimum required internal temperature to maintain the freshness of the products in the refrigerator is The control device 15 calculates the corrected appropriate blowout air volume necessary to obtain the temperature variation value ΔT ₂₅ (Wfit=f(Tout, ΔTmax)), outputs a control signal to the air volume variable device 14 connected to the blower 9,
Cooling operation is performed at this calculated appropriate blowout air volume until the start of the next defrosting operation.

As a result, the air volume variable device 14 operates, and the amount of air sent into the cold air circulation air path 7 by the blower 9 changes (W=Wfit), for example, the variation set value of the internal temperature is kept constant at ΔT ₂₅ . When maintaining the freshness of the products in the warehouse in this state, if the outside temperature changes from 25°C to 20°C, the control device 15 outputs an output to the air volume variable device 14 to change the air volume from W ₁ to W ₂ . .

In this case, if the operation is continued with the air volume W ₁ even though the outside temperature has fallen to 20℃, the internal temperature variation value will be ΔT ₂₀ , and the internal temperature variation will be greater than necessary to maintain the freshness of the product. In this case, the required refrigeration capacity will be _Q20 .

However, as mentioned above, if the air volume is changed to W ₂ so that the products can be kept together at the minimum ΔT ₂₅ required to maintain freshness, the required refrigerating capacity decreases to Q ₂₀ ', and as shown in Figure 5. Energy savings can be achieved by ΔQ′.

In addition, in the above embodiment, the case where the internal temperature variation setting value is maintained at the minimum value ΔT ₂₅ required to maintain the freshness of the products in the refrigerator was explained, but it is possible to set the temperature variation in the refrigerator at a much wider range by prioritizing energy saving over freshness management. In order to save energy, the internal temperature variation setting value may be set to ΔT ₂₅ ″, which is larger than ΔT ₂₅ in the above embodiment.

In this case, when the outside temperature is 25℃, the air volume is
The control device 15 outputs an output to the air volume variable device 14 so that the air volume becomes W ₁ ″ and when the outside temperature is 20°C, the air volume becomes W ₂ ″, thereby changing the required refrigerating capacity from Q ₂₅ ″.
Q ₂₀ ″, and energy savings can be achieved by the amount of decrease ΔQ″. Since this amount of decrease ΔQ″ is larger than the amount of decrease ΔQ′ in the embodiment described above, the energy saving is even greater.

〔Effect of the invention〕

As described above, the method for controlling the operation of a refrigerated open shower case according to the present invention is based on the method of controlling the operation of a refrigerated open shower case when the outside air is The temperature is calculated based on the air volume, and the air volume is adjusted after a predetermined period of time to maintain a constant temperature variation within the refrigerator, making the variation in temperature inside the refrigerator smaller than necessary. It is possible to maintain the freshness of the products in the refrigerator without having to worry about it, and it is possible to save energy.

Further, since the internal temperature variation set value can be freely set to any desired value, greater energy savings can be achieved by selecting this set value.

[Brief explanation of the drawing]

Fig. 1 is a control flowchart showing an embodiment of the method for controlling the operation of a refrigerated open show case according to the present invention, Fig. 2 is a vertical cross-sectional side view of the refrigerated open show case used in the method of the present invention, and Fig. 3 is a main part of the same. A front view of the internal temperature variation value setting device, No. 4
Figure 5 is a characteristic curve diagram showing the relationship between elapsed operation time, airflow volume and outside temperature, Figure 5 is a characteristic curve diagram showing the relationship between airflow volume, outside temperature, required refrigerating capacity, and internal temperature variation value. FIG. 1 is a vertical sectional side view of a refrigerated open storage case used in a conventional operation control method. 1...Show case body, 2...Front opening, 3
...Insulating wall, 4...Air outlet, 5...Suction port, 6...
...Duct board, 7...Cold air circulation air path, 8...Cooler, 9...Blower, 10...Product display room, 11...
...Product placement shelf, 12...Blowout air volume sensor, 13
...Internal temperature variation value setting device, 14...Air volume variable device, 15...Control device.

Claims (1)

[Claims] 1 The main body, which has an opening for entering and exiting products on the front side, is divided by a duct board into a product display room and a cold air circulation path in which a blower and a cooler are installed, and the end of the cold air circulation path is used to store the products. In a refrigerated open air case in which a blowout port and a suction port facing the upper and lower ends of an inlet/outlet opening are formed and the opening surface is closed with a cold air curtain, a blowout air volume sensor is provided, and the blowout air volume is measured after a predetermined period of time has elapsed after the start of cooling operation. Operation control of a refrigerated open case that calculates the outside air temperature from the airflow volume detected by a sensor, and then adjusts the airflow volume so that a predetermined internal temperature variation value is obtained under this outside air temperature. Method.