JPS6136147B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for controlling atmosphere in a refrigerator.

Generally, the atmosphere of a refrigerator is controlled by installing a temperature sensor inside the refrigerator and controlling the cooling means to maintain a set temperature based on the temperature detected by the temperature sensor. Furthermore, when using a cooling device that uses refrigerant such as Freon, the moisture inside the refrigerator condenses and adheres to the evaporator, making it necessary to periodically defrost the refrigerator.For this reason, multiple evaporators are installed in the refrigerator so that one is always on the other. The cooling effect of the evaporator is also maintained.

However, in the case of very large refrigerators such as prefabricated refrigerators, it is important not only to maintain a constant temperature throughout the refrigerator, but also to eliminate local temperature increases or decreases. In particular, when it comes to preserving fresh foods, the ideal storage temperature condition is a temperature close to the freezing point of the food, so if the internal temperature fluctuates widely or localized low temperature spots form, it can cause low temperature damage. become. Conventionally, in order to perform such atmosphere control, the cooling and defrosting control of the cooling device has to be strictly controlled, making the control device complicated and sophisticated and expensive, which is disadvantageous in terms of practical use.

In view of these problems, an object of the present invention is to provide a control method that can easily and reliably reduce the range of temperature fluctuations, equalize the temperature distribution over the entire interior of the refrigerator, and create a favorable constant temperature environment. do.

To this end, the present invention installs a plurality of evaporators inside the refrigerator and switches them to perform defrosting in sequence.The remaining evaporators control the cooling inside the refrigerator with a constant cooling capacity as a whole. Multiple temperature sensors are installed, and when any one of the temperature sensors detects a temperature that exceeds the set temperature inside the refrigerator by a predetermined temperature difference, the fans in the refrigerator except for the fan that is combined with the evaporator during defrosting are activated. It is characterized in that the temperature distribution inside the refrigerator is controlled to be uniform.

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

FIG. 1 schematically shows the components of a refrigerator in which the method of the present invention can be carried out. The refrigerator 1, which is a large refrigerator with a prefabricated structure, is intended to store fresh foodstuffs inside, and the temperature of the internal atmosphere is set to -3°C±0.7°C. As a cooling device for this purpose, a compressor 2 for compressing a refrigerant such as Freon is provided outside the refrigerator. As is well known, the refrigerant pumped from the compressor 2 passes through a condenser 3 and a reservoir 4, and is then branched into three directions, and is then branched into three directions, which are connected to solenoid valves 5a, 5b, 5c and expansion valves 6a,
6b, 6c sequentially to evaporators 7a, 7b, 7c.
be led to. The refrigerants vaporized in the evaporators 7a, 7b, and 7c are then combined and returned to the compressor 2 through the refrigerant evaporation pressure regulating valve 8, and this cycle is repeated. As is clear from the foregoing, this refrigerator 1 has three evaporators 7a, 7b, and 7c inside, and these evaporators are connected to fans 9a and 9, respectively.
b and 9c form a cooling unit. Electric heaters 10a, 10b, 10c for defrosting are attached to the evaporators 7a, 7b, 7c, respectively. Furthermore, inside the refrigerator 1, there are six electric temperature sensors 11a, 11b,
11c, 11d, 11e, and 11f are arranged in a distributed manner so that the local temperature near each can be detected.

A control device 12 provided to control the operation of each component device described above includes a timer circuit 13 and a temperature control circuit 14. The timer circuit 13 directly controls the energization of the solenoid valves 5a, 5b, 5c and the electric heaters 10a, 10b, 10c, and also controls the energization of the fans 9a, 9b, 9c together with the temperature control circuit 14. , this control is as shown in FIG.
That is, the timer circuit 13 always closes the solenoid valve associated with one of the evaporators every predetermined time t suitable for defrosting, cuts off the refrigerant supply, and at the same time energizes the electric heater to perform defrosting. During this time, the fan associated with the evaporator is completely stopped, regardless of the fan control by the temperature control circuit 14. When the defrosting of one evaporator is completed, that is, time t has elapsed, the defrosting of the other evaporator is switched to, and by repeating this, each evaporator is defrosted for time t and defrosted for time 2t. This is repeated, and always two evaporators are defrosted or cooled. Therefore, the interior of the refrigerator is always cooled with a constant cooling capacity by the two evaporators. Therefore, the range of temperature fluctuation can be kept small. Here, the operation of the fan other than defrosting is controlled by the temperature control circuit 14 to control the temperature inside the refrigerator, as will be described later.

Three temperature sensors 11a placed inside the refrigerator
11f gives a detection signal to the temperature control circuit 14, and the temperature control circuit 14 compares the average value of these temperatures with a preset internal temperature and controls the fans 9a to 9.
c is appropriately controlled and maintained at a predetermined temperature. Of course, if cooling is required, the fans of the cooling units other than the cooling unit being defrosted will be driven, and if cooling is not required, the fans will be stopped. This temperature control circuit also detects whether the temperature of each of the temperature sensors 11a to 11f is within a preset temperature range, which is the set temperature inside the refrigerator plus a temperature range of, for example, ±0.5°C. do. If it is detected that the detected temperature of any one temperature sensor is out of this range (meaning that the average temperature is at the set temperature and there is a local temperature abnormality), the temperature control circuit 14 drives the fan and disturbs the atmosphere inside the refrigerator.
Aim to make the temperature distribution uniform.

As explained above, according to the present invention, the range of overall temperature fluctuation can be reduced with a very simple device, and local temperature changes can also be quickly controlled within the allowable range, resulting in extremely large effects. It will be done.

Note that the internal cooling control can be performed based on any one of the temperature sensors, or a fan can be provided separately for control.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of a refrigerator that can implement the control method of the present invention. Figure 2 is a time chart of the operation of each component. 1...refrigerator, 2...compressor, 3...condenser,
4... Reservoir, 5a, 5b, 5c... Solenoid valve, 6a, 6b, 6c... Expansion valve, 7a, 7b,
7c... Evaporator, 8... Regulating valve, 9a, 9b, 9
c...Fan, 10a, 10b, 10c...Electric heater, 11a-11f...Temperature sensor.

Claims (1)

[Scope of Claims] 1. A refrigerator equipped with cooling units each having an evaporator and a fan at a plurality of locations inside the refrigerator,
In addition to controlling each cooling unit to switch to defrosting operation in sequence, the remaining cooling units control cooling operation and stop so that the temperature inside the refrigerator falls within the set temperature range, and temperature sensors are installed at multiple locations inside the refrigerator. is arranged, and when any temperature sensor detects a temperature that occurs within a predetermined temperature range from the set temperature,
In order to make the temperature distribution in the refrigerator uniform regardless of the cooling operation/stop of the cooling unit, the fan in the refrigerator is controlled to be driven except for the fan of the cooling unit during the defrosting operation. How to control the atmosphere of a refrigerator. 2. The refrigerator atmosphere control method according to claim 1, wherein the defrosting operation is switched every predetermined time period. 3. The atmosphere of the refrigerator according to claim 1, wherein the cooling operation/stop of the cooling unit is controlled based on a comparison between the average value of the temperatures detected by all the temperature sensors and a set temperature. Control method. 4. Atmosphere control of a refrigerator according to claim 1, characterized in that the cooling operation/stop of the cooling unit is controlled based on a comparison between a temperature detected by a temperature sensor and a set temperature as one reference. Method. 5. The atmosphere of the refrigerator according to claim 1, wherein the fan that is driven when any temperature sensor detects a temperature exceeding a predetermined temperature range from the set temperature is a fan of a cooling unit. Control method. 6. Claim No. 6, characterized in that the fan that is driven when any temperature sensor detects a temperature exceeding a predetermined temperature range from the set temperature is a fan provided in a refrigerator other than the cooling unit. The method for controlling the atmosphere of a refrigerator according to item 1.