ITPN20000074A1 - REFRIGERATOR APPLIANCE WITH A MULTIPLE OF COMPARTMENTS - Google Patents

Description

Description

of the patent for industrial invention entitled:

"REFRIGERATOR WITH A PLURALITY OF

DISAPARTED "

The present invention relates to a refrigerator appliance, in particular of the domestic type, comprising at least two cabinets for containing and storing food products at different temperatures.

Refrigerating appliances with a refrigeration compartment and a freezing compartment are commonly known. These appliances are equipped with two separate refrigeration circuits, one for each compartment, or with a single refrigeration circuit comprising two evaporators which can be selectively fed through a valve that diverts the flow of the refrigerant fluid in order to respond to the requests for cold in the two disappearances of the appliance. . The first solution is obviously more expensive, given the duplication of the circuits and therefore of the related components. The second solution, on the other hand, offers a lower efficiency and an unsatisfactory behavior from the point of view of efficiency.

Patent EP 0 246 465 describes a refrigeration circuit for domestic refrigeration appliances which essentially comprises a compressor, a condenser and two evaporators in series arranged respectively in a storage compartment and in a freezing compartment. The compressor is of the rotary type, equipped with a high starting torque. Therefore, to prevent the pressures from balancing in the entire circuit during compressor shutdown periods, it is proposed to re-insert a thermostatically controlled solenoid valve, which is equipped with an input from the condenser and two outputs to the evaporators. The two solenoid valve outputs can both be closed when the compressor is stopped and can be selectively opened when the compressor is running. The solution described in this patent has proved to be only theoretical, given that such a solenoid valve is difficult to manufacture and would, however, involve additional energy consumption for its operation.

The much more recent patent WO 00/49344 proposes a solution similar to that of the patent EP 0 246 465, but without defining the type of compressor and describing a valve only in terms of operation and not of construction. In particular, when the evaporators are in series (Fig. 4) it cannot be understood how valve 1 in position S3 can only power evaporator 5B. In this position, in fact, it appears inevitable that almost all the refrigerant fluid also passes into the evaporator 5A, thus feeding both evaporators. In fact, the solution of this patent represents yet another only theoretical attempt to create a refrigerating appliance to achieve a reduction in energy consumption through the optimization of the refrigeration circuit.

Instead, this object can be achieved according to the present invention by using the combination of a new type of compressor with variable power (or refrigerating capacity) and a new valve solution, as defined in the claim of this patent.

Advantages and features of the invention will become evident from the following description, by way of example and not of limitation, with reference to the attached drawings, in which:

Figure 1 represents the diagram of the most recent state of the art, according to the patent WO 00/49344;

- Figure 2 schematically represents in section a refrigerating appliance equipped with a refrigerating circuit according to the invention; Figure 3 represents a diagram showing the need for refrigeration as a function of temperature variations in the refrigeration compartment and in the freezing compartment from the appliance of Fig.l. As already mentioned, the most recent state of the art is represented in Fig. 1, which shows a refrigeration circuit with a compressor 2, a condenser 3 and two evaporators in series 5a and 5b. A three-way valve I is inserted between the condenser 3 and the evaporators 5a and 5b. In the YES position, the valve closes the passage of refrigerant fluid towards both evaporators. In position S2, the valve allows the passage of the refrigerant first through the evaporator 5a then through the evaporator 5b. Finally, in position S3, the valve should close the passage P2 towards the evaporator 5a and allow the passage of the refrigerant fluid only through the evaporator 5b. The latter situation, however, is not understandable because valve I. as shown, cannot close the passage P2. Furthermore, even if a different type of valve could achieve this circuit condition, the balancing of the refrigerant circuit could not be correct, as shown, since the two evaporators require considerably different quantities of cold.

The solution according to the present invention is schematically represented in Fig. 2, where a refrigerating appliance is shown comprising a refrigeration compartment 10 and a freezing compartment 11, each equipped with a respective evaporator 12 and 13. The two evaporators are connected in series in the refrigeration circuit, which also includes a compressor 14 and a condenser 15. Each evaporator is also associated with a respective restrictor, or capillary tube, 16 and 17.

According to the invention, the compressor 14 is a compressor with variable power, or cooling capacity, and the regulation of the flow of refrigerant fluid in the circuit is carried out by means of valve means inserted between the condenser 15 and the capillaries 16 and 17. More precisely, these means they can consist of a one-way valve 18 and a diverter valve 19, both controlled by two thermostats (not shown) arranged respectively in the disappearances 10 and 1 1. The valve 18 allows to open or close the passage of refrigerant fluid to the evaporators. The valve 19 actually allows to supply both evaporators in series or just the evaporator 13 of the freezing compartment. Naturally, the two valves 18 and 19 could be replaced by a three-way valve, in the hypothesis that it is possible to produce a valve of this type with safe operation and reduced energy consumption.

The correct balance of the refrigerant circuit is then obtained. appropriately dimensioning the capillaries 16 and 17; in particular, providing for the capillary 16 a greater flow rate than that of the capillary 17.

The actual energy saving, which is the main purpose of the proposed solution, is therefore obtained from the combination of different elements.

The main element is constituted by the use of a variable power compressor 14, which is equipped with its own autological control able to independently select its speed (and therefore the necessary power) on the basis of a combination (for example, the arithmetic mean) of the working percentages of the two disappearances of the refrigerator and of the ON periods (or of operation) of the same disappearances, favoring the one that requires the longest operating time.

Fig. 3 shows a diagram showing the need for refrigeration as a function of the temperature variations in the refrigeration and freezing compartments (respectively shown in abscissas and ordinates) of a typical refrigeration appliance. The letters A-H indicate the operating bands at the various compressor speeds (with A the lowest speed, with H the highest speed). The rectangles represent the adjustment areas of the appliance at different ambient temperatures (Ta). The algorithm of the autological control of compressor 14 can be, for example, based on the following functional data:

where is it :

RT indicates the percentage of work of the refrigerator appliance, and ON indicates the operating time of the same.

A further element that allows for effective energy savings is the use of valves 18 and 19, pulse-controlled. The actuation of these valves makes it possible to close the circuit in the OFF phases of the refrigeration appliance, preventing the passage of hot refrigerant fluid from the condenser 15 towards the evaporators 12 and 13. Furthermore, the valve 19 effectively allows the evaporators to be supplied in a selective, according to the cooling requirements of the respective compartments of the appliance.

Finally, the differentiation of the flow rates of the capillaries 16 and 17 increases the flexibility of the refrigerant circuit to provide a cooling capacity that responds to the thermal load of the appliance, both with respect to the independent use of the two compartments, and with respect to the different conditions of the same (temperature environment, position of thermostats, door opening, etc.).

Claims (3)

CLAIMS 1. Refrigerating appliance, particularly of the domestic type, comprising at least two compartments (10,11) for containing and storing food products at different temperatures as well as a refrigerating circuit comprising a compressor (14), a condenser (15), valve means (18 , 19) for the deviation of the refrigerant fluid and an evaporator (12,13) located in each compartment, said evaporators being connected in series with each other, characterized by the fact that said compressor (14) is a variable power compressor and that said means valves consist of a one-way valve (18) and a diverter valve (19) for selectively feeding said evaporators by means of respective restrictor means (16,17). 2. Refrigerating appliance according to claim 1, characterized in that said restricting means (16,17) are capillary tubes having different flow rates, the capillary (16) associated with the evaporator (12) of the refrigeration compartment having a higher flow rate than the capillary ( 17) associated with the evaporator (13) of the freezing compartment. 3. Refrigerating appliance according to claim 1 or 2, characterized in that the compressor (14) is equipped with its own autological control able to independently select its speed on the basis of a combination of the working percentages of the two compartments (10, 11) of the refrigerator appliance and the ON periods of the same compartments, favoring the one that requires the longest operating time.