JPH01159573A - refrigerator - Google Patents

Abstract

PURPOSE: To achieve quick freezing of a food and prevention of inner temperature rise by detecting the ambient temperature and shortening the quick freezing time through a direct cooling plate if the ambient temperature is high. CONSTITUTION: The refrigerator is provided with a second cooler 6 serving as a direct cooling plate for freezing a mounted food in addition to a first cooler 4 for normal refrigerating operation. Quick cooling operation time employing the second cooler 6 is set, by a controller 9 being inputted with the ambient temperature detected by a thermistor 10 fixed to an appropriate point on the refrigerator body, to be short when the ambient temperature is high enough to cause inner temperature rise at the time of quick freezing and to be long when the ambient temperature is not high enough to cause a significant inner temperature rise even at the time of quick freezing. According to the arrangement, quick freezing of a food can be carried out as long as possible while preventing inner temperature rise effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a refrigerator equipped with two coolers and having a quick freezing function.

<Prior Art> In recent years, interest in home freezing has increased due to the diversification of dietary habits, and there is a demand for a quick freezing function for household refrigerators.

In order to deal with this, when performing quick freezing conventionally, the signal from the thermostat that detects the temperature in the freezer compartment is ignored, and the compressor is operated continuously for a certain period of time to control the temperature in the freezer compartment, that is, the temperature of the cold air blown out through the cooler. Methods are being adopted to reduce the temperature as much as possible and speed up the freezing rate.

However, this method cannot be expected to significantly improve the freezing speed since cooling is performed using cold air. For this reason, a refrigerator having a cycle as shown in FIG. 3 is being considered, which is equipped with a second cooler 6 serving as a direct cooling plate in addition to the ordinary cooler 4. In this cycle, normally, the solenoid valve 7 is opened and the refrigerant is allowed to flow through the first cooler 4 and the fan 8
Blows out cold air to cool the freezer and refrigerator compartments. In addition,
In this case, since the second capillary tube 5 acts as a resistance, the refrigerant hardly flows into the second cooler 6.

During quick freezing, the solenoid valve 7 is closed and the compressor 1 and condenser 2 are closed.
．． The refrigerant flows through the first capillary tube 3 toward the second cooler (direct cooling plate) 6 . The second cooler (direct cooling plate) 6 is provided in a part of the freezing chamber, and by sufficiently reducing the pressure of the refrigerant through the second capillary tube 5,
The refrigerant evaporation temperature in the second cooler (direct cooling plate) 6, that is, the surface temperature of the direct cooling plate, can be cooled to about -50°C. By placing food on this direct cooling plate 6, it becomes possible to freeze the food more quickly than ever before.

However, in this cycle, during rapid freezing, the first
Since the refrigerant does not flow into the cooler 4, there are the following problems.

<Problems to be solved by the invention> In the cycle shown in Fig. 3, during quick freezing, the refrigerant flows into the second cooler (direct cooling plate) 6 and quickly freezes the food on the direct cooling plate. Since no refrigerant flows into the container 4, the temperatures in the freezer compartment and refrigerator compartment gradually rise during rapid freezing. Therefore, the quick freezing time cannot be made too long.

For this reason, even if quick freezing operation for a certain period of time is sufficient to quickly freeze food, as in the case of conventional quick freezing operation using cold air, the temperature in the freezer or refrigerator compartment may rise excessively, and vice versa. If the internal temperature rise is suppressed within an allowable range, a problem arises in that food does not freeze completely. Therefore, it is difficult and rare to satisfy both the requirements of rapid freezing of food and prevention of internal temperature rise.

Means for Solving the Problems> The present invention has been made in view of the above-mentioned problems, and in order to simultaneously satisfy the rapid freezing of food and the prevention of temperature rise inside the refrigerator, the compressor is turned on for a certain period of time during rapid freezing. Continuous operation, and within that time, the time is divided between when the refrigerant flows through the first cooler and when it flows through the second cooler, and by a certain mode using both cold air and a direct cooling plate. It is basically based on rapid freezing. In addition, since the degree of temperature rise inside the refrigerator varies depending on the ambient temperature of the refrigerator, a sensor is installed to detect the ambient temperature, and the mode is changed in stages depending on the ambient temperature, and when the ambient temperature is high, a second cooler is activated. When the flow time is short and the ambient temperature is low, the flow time through the second cooler is controlled to be longer.

Figure 2 shows the general shape of a food freezing curve. In order to freeze food without damaging its structure, it is necessary to quickly pass through the zone of maximum ice crystal formation (part B) in Figure 2 to form fine ice crystals within the cells of the food. A
, C are not significantly affected by the cooling rate. Therefore, rapid freezing is performed using a direct cooling plate during the time period when the food passes through range B, and parts A and C are frozen using cold air using the first cooler or second cooler. This is an operating mode that allows for both quick freezing, which is effective for improving product quality, and prevention of temperature rise inside the refrigerator.

Please note that the temperature rise inside the refrigerator depends on the ambient temperature level of the refrigerator.
Rapid freezing operation using direct cooling plates is also regulated by this regulation. Therefore, we change the mode in about 3 stages depending on the ambient temperature, set the time that can be quickly frozen using the direct cooling plate in each ambient temperature range, and perform quick freezing using the direct cooling plate for as long as possible to adjust the freezing time of the food. The aim is to shorten the time.

<Embodiment> FIG. 1 is a block configuration diagram of a refrigerant flow path of a refrigerator-freezer for explaining one embodiment of the present invention.

In normal refrigeration operation, the solenoid valve 7 is open as in the conventional case, so the refrigerant such as 7c1 gas is supplied to the compressor 1 - condenser 2 - first capillary tube 3 - solenoid valve 7 - first cooler 4 - It flows through a flow path called compressor l. Further, the cold air cooled by the first cooler 4 is blown into the refrigerator by a fan 8 to cool the interior of the refrigerator. During quick freezing operation, the solenoid valve 7 is closed, so that the refrigerant flows through the compressor l - condenser 2 - first capillary tube 3 - second capillary tube 6 - second
It is converted into a flow path between the cooler 6 and the compressor 1 and flows therethrough. The second cooler 6 is a direct cooling plate disposed in the freezer and rapidly freezes food placed on the direct cooling plate.

In the refrigerator having the above-mentioned refrigerant passage, a Sunmister IO is installed at an appropriate position such as the wall, door, bottom or top end of the refrigerator body to detect the ambient temperature, and the outside temperature signal detected by this thermistor 10 is sent to the control circuit. The signal is input to the built-in controller 9.

The controller 9 controls and sets the operating conditions of the compressor 1, the opening/closing of the solenoid valve 7, and the operation of the fan 8 in accordance with the outside temperature signal. The broken line in the figure shows this control system.

In this embodiment, three rapid freezing control modes are set depending on the ambient temperature as described below.

(1) Ambient temperature>20°C (120 minutes of continuous compressor operation) Cold air 40 minutes → Direct cooling plate 40 minutes → Cold air 40 minutes (11) to °C
Ambient temperature: 20°C (continuous compressor operation 120 minutes) Cold air 20 minutes → Direct cooling plate 60 minutes → Cold air 40 minutes (11D) Ambient temperature: 10°C (compressor continuous operation 90 minutes or 120 minutes)
Direct cooling plate only (90 minutes or 120 minutes) According to an experiment at an ambient temperature of 30°C, the internal temperature of the refrigerator during quick freezing using a direct cooling plate increases by approximately 25 minutes per 40 minutes.
℃, and the time of vomiting is considered to be the limit (1)
Set the mode like . It has also been experimentally confirmed that ordinary foods can be sufficiently frozen in mode (1) for 120 minutes.

When the ambient temperature is about 15° C., the rate of increase in temperature inside the refrigerator is also small, so the quick freezing time using the direct cooling plate can be set to about 60 minutes. Therefore, mode (11) is used when the ambient temperature is 20°C.

Furthermore, when the ambient temperature drops to 10"C or less, the difference between the internal temperature of the refrigerator compartment and the ambient temperature becomes very small, so even if you perform quick freezing using a direct cooling plate for 90 to 120 minutes, the internal temperature will decrease. There is little rise, and rapid freezing is possible using only direct cooling plates.

The above setting time depends on the size of the refrigerator, freezing capacity,
sb may vary depending on the heat insulation performance, and is not limited to the above value. Furthermore, it is also possible to further divide the ambient temperature into more finely divided sections to more accurately respond to changes in ambient temperature.

The fan 8 may be configured to blow only the first cooler 4 to circulate the cold air into the refrigerator. may also be supplied. By supplying cold air using both coolers 4 and 6, it is possible to suppress the rise in internal temperature in the quick freezing operation mode.

<Effects of the Invention> As described above, according to the present invention, in a refrigerator having a quick freezing cycle, food can be frozen rapidly using a low-temperature direct cooling plate, and the quick freezing operation mode can be changed to a freezing cooler. This method combines cooling with cold air using a cooling board and cooling with a direct cooling plate, and detects the ambient temperature. The operating mode is changed to increase the cooling time, and the system is set to perform rapid freezing operation using the direct cooling plate for as long as possible. Therefore, it has the remarkable effect of being able to effectively achieve rapid freezing of food and prevention of temperature rise inside the refrigerator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a refrigerant flow path of a refrigerator for explaining one embodiment of the present invention. Figure 2 is a typical freezing curve in the food freezing process. FIG. 3 is a block diagram of a refrigerant flow path in a conventional refrigerator-freezer. ! ... Compressor, 2... Condenser, 3... First capillary tube, 4... First cooler, 5... Second
capillary tube, 6... second cooler (direct cooling plate), 7... solenoid valve, 8... fan, 9... controller, 10... thermistor. Agent Patent attorney Takeshi Sugiyama (and 1 other person) Figure 1

Claims (1)

[Claims] 1. A compressor, a condenser, a first capillary tube, a solenoid valve, and a first cooler are connected in an annular manner, and branched from the inlet side of the solenoid valve and connected to the solenoid valve and the first cooler. A second capillary tube and a second capillary tube in parallel.
A refrigerator having a refrigeration cycle in which a series-connected body of coolers is arranged and an outlet of the second cooler is connected to an outlet side of the first cooler, a temperature sensor for detecting outside temperature is provided, and the compressor A quick freezing operation mode is provided in which the solenoid valve is switched for a certain period of time within the continuous operation period of the machine to convert the refrigerant flow path from the first cooler to the second cooler, and the outside air detected by the temperature sensor is provided. A refrigerator comprising a control system that controls the time of the quick freezing operation mode according to a temperature level.