RU2362097C2 - Refrigerating device - Google Patents

Abstract

FIELD: instrument making. ^ SUBSTANCE: two-door refrigerating device comprises refrigerating system, fresh foodstuffs chamber and frozen foodstuffs chamber. Note here that aforesaid refrigerating system comprises at least two evaporators. Evaporator, which freezes the frozen foodstuffs, chamber envelopes the latter. At least one its section passes inside aforesaid chamber for frozen foodstuffs. ^ EFFECT: electric power savings, higher efficiency. ^ 13 cl, 3 dwg

Description

The invention relates to a two-door type cooling device (1) having a chamber for fresh food products and a chamber for frozen food products equipped with energy-saving elements.

In the modern technical level, there are many solutions related to cooling devices, which contain two separate and with independent access chambers: one for fresh food products and the other for frozen food products. In particular, in the market for cooling devices, there are two types of cooling devices having freezer compartments accessible through a specialized closing system, such as a door, and therefore the user does not need to open the fresh food chamber to gain access to the compartment containing frozen food products. Therefore, in this sense, the frozen food chamber is independent of the fresh food chamber. Two such types of cooling devices are the so-called "two-door" and "combined" cooling devices.

"Combined" cooling devices are usually characterized in that they have large freezer compartments, generally having a volume exceeding 70/80 liters.

Due to a number of technical and aesthetic factors, including the large size, the chamber for frozen food products of these types of cooling devices is located at the bottom of the device and is made of plastic material. Therefore, in the combined cooling devices according to the prior art, the frozen food chamber consists of a casing made of plastic material inserted into a chair-shaped support structure that supports the fresh food chamber.

The plastic casing used in the combined cooling devices for the chamber for frozen food products is designed in such a way as to enable the insertion of a number of elements, including drawers, shelves and an evaporator device.

In cooling devices known as “two-door” cooling chambers, the frozen food chamber is located at the top of the device and has a reduced size: while in “combined” cooling chambers, the volume of the frozen food chamber can be even 40-50% of the volume of the chamber for fresh food products, in "two-door" cooling devices, the volume of the chamber for frozen food products in most cases is less than 30% of the volume of the chamber for fresh food products; typically a frozen food chamber has a volume of less than 60 liters. In "two-door" cooling devices, the smaller volume of the chamber for frozen food products makes it possible to produce it from aluminum. There are several shelves inside the frozen food chamber, which can be metal nets or solid shelves made of plastic or glass material. As this will become apparent later, the aluminum structure has the advantage of allowing the evaporator to pass around the entire structure, thus remaining inside the walls of the frozen food chamber.

In all known solutions of cooling devices, food products are cooled in a known manner by means of a cooling system containing an engine driving a compressor, the task of which is to compress a gas, generally R134a or R600a, which at the same time reaches high pressure, and keep it in a gaseous state and send into a condenser, where it condenses and becomes a high-pressure liquid; thanks to the coil located on the rear wall of the cooling device, the liquid dissipates its heat and cools. Subsequently, high-pressure liquid refrigerant passes through an expansion device.

The expansion device is a unit installed between the condenser and the evaporator system of the cooling device, and has the function of providing a sharp drop in pressure.

Therefore, the expansion device acts as a differential pressure. The presence of a pressure differential in the cooling cycle is very important because it causes a change in the boiling point of the gas. Without this pressure fluctuation, the liquid refrigerant cannot significantly lower its temperature, reaching several tens of ° C below zero, and therefore cooling will not occur; the system would be just a simple container of a cooling element, for example, R134a or R600a.

The refrigerant leaving the expansion device, generally consisting of a small tube called a “capillary,” is then fed into a coil called an evaporator, which passes inside the walls of the cooling device to absorb heat from the inside of the chamber to be cooled. The liquid refrigerant having absorbed heat evaporates and returns to the gaseous state. This makes it possible to obtain a cooling process inside the cooling device.

After that, gas is supplied to the compressor and the cycle starts again.

Depending on the type of cooling device, the evaporator can be provided in two different and additional ways.

In the "two-door" cooling devices according to the current technical level, the evaporator is made of two parts, one of which is connected to the chamber for frozen food products, and the other is connected to the chamber for fresh food products, and installed between the outer part of the cooling device and chambers; then an insulating foam is placed between the two walls. In particular, the evaporator completely surrounds the chamber for frozen food.

In "combined" cooling devices, in which the chamber for frozen food products is very large, and the chamber structure is made of plastic material, the cooling system contains an evaporator device: an evaporator, which in the "two-door" cooling chambers is a coil located outside the chamber to be cooling, in the "combined" cooling devices is provided through its own permanent tubular structure located in the form of shelves inside the chamber. Evaporator device solutions are known from GB 2133518 and GB 2133519.

Increasing energy saving requirements for cooling devices have led to the definition of energy consumption classes (denoted by alphabetic characters from A ++ to F, in order of increasing consumption), which are useful as a guarantee for the buyer, while at the same time leading manufacturers to pay even more attention to the aspect of energy consumption.

In this context, and being the best solutions for an already well-rooted cooling system (circuitry containing a compressor, condenser, expansion device, and evaporator), the focus was on finding solutions that provide better insulation and with even more efficient motor-driven compressors. However, such decisions involve high research costs, and the improvements achieved are often not very noticeable and do not have adequate payback.

It is an object of the present invention to solve the problems associated with known cooling devices by providing a cooling device known as a “two-door” type device, which makes it possible to save electrical energy and obtain excellent performance.

An additional objective of the present invention is to provide a solution to the problems of the prior art, and the solution is both economical and effective.

The tasks are achieved by means of a two-door type cooling device containing

- cooling system,

- a chamber (2) for fresh food products and

- a chamber (3) for frozen foods,

moreover, the cooling system contains at least two evaporators (5, 14, 31, 32), while the evaporator cooling the chamber for frozen foods covers the specified chamber for frozen foods, characterized in that at least one section (5) the evaporator (14, 31), the cooling chamber (3) for frozen food passes inside the chamber (3) for frozen food.

Preferably, the frozen food chamber has a volume of less than 60 liters and has a volume of less than 30% (thirty percent) of the volume of the fresh food chamber, has a size such that it is possible to insert a separation shelf for placing food, and also has such a size, which provides the ability to insert only one separation shelf.

In addition, it is preferable that the height of the spaces defined by the dividing shelf inside the chamber for frozen food products is such as to enable the placement of food products, in particular not less than 10 cm.

The shelf is preferably formed only by the section of the evaporator passing inside the cell for frozen food, and has a bearing surface for food, on the lower side of which there is a section of the evaporator passing inside the chamber for frozen food.

Preferably, the support surface for food is made of plastic material or glass.

The cooling system preferably comprises means for cooling the chamber for frozen foods, regardless of the chamber for fresh foods.

The cooling means preferably comprises a solenoid valve and two capillaries connected to two chambers of the cooling device.

The solenoid valve is preferably controlled by an electronic temperature switch and provides hydraulic switching between the two capillaries.

Additional objects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings, given by way of non-limiting example.

Figure 1 shows a front view of a cooling device in accordance with the invention.

Figure 2 shows a transparent view of a cooling system of an embodiment of a cooling device in accordance with the invention.

Figure 3 shows a cooling system in accordance with a second embodiment of a cooling device according to the invention.

Figure 1 shows a "two-door" cooling device, generally indicated by the reference number 1. The cooling device comprises two chambers (chamber (2) for fresh food products and a chamber (3) for frozen food products) that are independently accessible from each other through the corresponding closing systems (6, 7).

In Fig. 1, closing systems (6, 7), for example doors, are shown in the open position to show the inside of the chamber (2) for fresh food products and the chamber (3) for frozen food products.

For simplicity, figure 1 does not show the cooling system of the cooling device completely. The system shown in FIGS. 2 and 3 and further described below contains the known elements described above, that is, a compressor, a condenser, an expansion device (in particular one or more capillary tubes) and one or more evaporators.

As already described in detail at the beginning of the present description, the “two-door” cooling device of the invention comprises a chamber (3) for frozen food products located in the upper part of the cooling device and having a reduced size; in particular, the size is such as to enable the insertion of only one partition shelf (4). It is assumed that in the preferred embodiment, the spaces (12, 13) defined by the shelf (4) inside the chamber (3) for frozen food products are large enough to accommodate food products. Although they can vary from device to device depending on technical and aesthetic requirements, usually spaces have a height of at least 10 cm.

As you can see, looking at these three drawings, the chamber (3) for frozen food products contains an additional section (5, 14) of the evaporator, that is, that element of the internal cooling system in which liquid refrigerant passes (for example, R134a, R600a, freon).

According to the invention, an additional section (5, 14) of the evaporator extends outside the chamber for frozen food products and leaves at least one of the walls, thus passing inside the chamber (3) for frozen food products.

Therefore, according to the invention, the cooling device (1) has an evaporator section, hereinafter referred to as an “external evaporator” (14) and indicated in FIGS. 1 and 2 by a dashed line, which, as in the prior art, passes around a chamber (3) for frozen food products and chamber (2) for fresh food products, as well as another section of the evaporator, hereinafter referred to as the "internal evaporator" (5) and indicated in Figures 1 and 2 by a solid line that runs inside the chamber (3) for frozen food products.

In more detail, FIG. 2 shows a preferred embodiment of the cooling system of a cooling device according to the invention: a compressor (15) compresses a refrigerant (e.g., freon or R134a or R600a) in a gaseous state in a condenser (16) in which it condenses and cools down.

When the refrigerant is in a liquid state, it passes through a filter (17), which traps any impurities present in the circuit, and then passes through a capillary tube (20) until it enters the evaporator.

The refrigerant passes in the evaporator, consisting of a system of tubes, mainly located in the form of a coil, passing mainly inside the walls of the refrigeration device, and then returns to the compressor (15). Along this path from the capillary to the compressor, the cooling element in the liquid state absorbs heat and evaporates, thereby cooling the inside of the cooling device.

With reference to figure 2 it should be noted that, in addition to passing inside the walls of the cooling device, the evaporator according to the invention also leaves the point (18) of the wall of the chamber (3) for frozen food and passes inside the volume of the chamber for frozen food. This open section of the evaporator (5), called the "internal evaporator", enters again into the walls of the refrigeration device at the point (19) of the frozen food chamber (3). From this point, the “internal evaporator” (5) again becomes the “external evaporator” (14) and resumes its path hidden from the eyes inside the walls of the cooling device (1) up to the compressor (15). Unexpectedly, this technical solution made it possible to produce a cooling device in which, at the same volumes, the food is cooled in the chamber (3) for frozen food with energy conservation: an increase in the cooling region actually allows the cooling system to absorb more calories from the frozen food chamber , without the need to increase the operating cycles of the system (i.e., the periods during which the compressor is on), and therefore provides lower reduction in energy consumption without the need to increase compressor power or improve insulation elements. In addition, the location of the "internal evaporator" (5) is such that, in order to improve the cooling of the frozen food chamber (3), the cooling evaporating surface is transferred inside the frozen food chamber.

To make this phenomenon easier to understand, one should turn to the rules of thermodynamics: a cooling device (1) is a machine that takes heat from a heat source (food products inside the chamber) and gives it to another heat source (cooling element), and from it to an external one environment due to the work performed by the machine itself, which takes energy from the electrical network. The amount of heat (Q) exchanged between the two sources is proportional to the area (S) of evaporation and the temperature difference between the two sources (Q = kS (T ₂ -T ₁ )). In the ideal case, according to the first law of thermodynamics, the amount of heat (Q) should be equal to the energy (E) consumed from the electrical network, but in fact due to different scatterings between these two physical quantities there is only proportionality.

It is clear from the above description that the same amount of heat (Q) can be absorbed inside the cooling device if the evaporation area (S) increases and the temperature difference (T ₂ -T ₁ ) between the two heat sources decreases; in other words, the same calories can be absorbed from the inside of the frozen food chamber if the evaporation area increases and at the same time the difference between the evaporator temperature T ₁ and the food storage temperature T ₂ decreases. With an ideal machine, relative to the efficiency of the Carnot cycle given by n = (1-T ₁ / T ₂ ), the closer T _{1 is} to T ₂ , the less is the energy E = n * Q that the machine should consume from the electric network. Therefore, it is clear that by increasing the evaporation area, it is possible to reduce the consumption of the cooling device (1).

In accordance with the invention, an increase in the evaporation area is possible due to the “internal evaporator” (5), that is, the section of the evaporator, which, in addition to completely enclosing the chamber (3) for frozen food, is kept between the walls of the cooling device and the outer walls of the cells for fresh food (2) and / or for frozen food (3), also passes inside the chamber (3) for frozen food.

Figure 3 shows a cooling system, that is, a schematic diagram of a cooling system, of a second embodiment of a two-door type cooling device according to the invention. The two-door type cooling device has two chambers, namely a chamber (3) for frozen food products and a chamber (2) for fresh food products, placed through respective evaporators 31 and 32.

The cooling system includes a compressor (15), upstream, from which a condenser (16), a hot tube (33), a filter (17) and a three-way solenoid valve (34) are located, which is controlled by an electronic temperature relay (40); the cooling system is divided into two schemes, represented by two capillaries, namely the capillary (35) of the cooling chamber and the capillary (36) of the freezer, connected to an electromagnetic valve (34), which can perform hydraulic switching between the two capillaries (35) and (36) so that they can be alternately powered by the compressor (15) depending on whether it is only necessary to cool the chamber (3) for frozen food or both the chamber (2) for fresh food and the chamber (3) for frozen food.

Both capillaries (35) and (36) cross the return pipe (39) in the first heat exchanger (37), from which they exit, following separate paths.

The capillary (35) of the cooling chamber passes through a second heat exchanger (38) and then moves the liquid refrigerant circulating inside to the top of the evaporator (32) of the chamber (2) for fresh food.

After passing through the entire evaporator (32) of the chamber (2) for fresh food products, the liquid returns and passes through the second heat exchanger (38), thereby absorbing heat from the capillary (35) of the cooling chamber, and then enters the evaporator of the chamber (31) for frozen food products. In a two-door cooling device, the coil of the evaporator of the chamber (31) for frozen food products covers the entire external surface (section called the "external evaporator") of the chamber (3) for frozen food products and in accordance with the invention before completing the path to the return tube (39) and return to the compressor (15) also passes inside the frozen food chamber (3) (section called an “internal evaporator” (5)), as shown with reference to FIG. 2.

In contrast, the capillary (36) of the freezer passes directly into the upper part of the evaporator of the chamber (31) for frozen food, and therefore without passing through a second heat exchanger (38).

The electronic control system of the refrigeration device according to the embodiment shown in FIG. 3 consists of a first temperature sensor (42) located in the fresh food chamber (2), which provides information on the air temperature in the fresh food chamber (2) for electronic temperature relay (40); similarly, the second temperature sensor (43) sends information about the air temperature in the chamber (3) for frozen food products to the same electronic temperature switch (40).

Thus, the logic of control of the electronic temperature relay (40) can, depending on the values read by the temperature sensors (42, 43), decide from time to time whether to cool both chambers (2, 3) in cascade or only the camera (3) for frozen food products by sending a corresponding signal to the electromagnetic valve (34), which, in turn, switches the liquid refrigerant either to the capillary (35) of the refrigeration unit or to the capillary (36) of the freezer.

Figure 3 also shows the third sensing element (41) located on the evaporator (32) of the chamber (2) for fresh food products and used to control the defrosting of the evaporator.

Two exemplary embodiments of the two-door type cooling devices of the invention provide energy conservation due to the larger evaporation area obtained by the evaporator section passing inside the frozen food chamber.

In a preferred embodiment, the section of the evaporator passing and visible inside the chamber for frozen food products ("internal evaporator" (5)) is made in the form of a coil, the straight sections of which have a length almost corresponding to the depth of the chamber (3) for frozen food, the loops of the coil are close enough to be used as a bearing surface for food products. Therefore, this type of solution can be used as a shelf inside the chamber for frozen food. According to the preferred embodiment shown in FIGS. 1 and 2, the evaporator extends around the side walls (9), the upper wall (11) and the lower wall (10) of the frozen food chamber, taking into account that it leaves the back wall ( 8) (that is, opposite the user who is standing in front of the cooling device (1) and opens the corresponding door (6) of the chamber (3) for frozen food). After passing inside the chamber (3) for frozen food products, the evaporator enters again into the rear wall (8), passing inside the other walls of the chamber for frozen food products and returning, as described, to the compressor. However, it does not matter for the present invention whether the “internal evaporator” (5) leaves the back wall (8) or any other wall (9, 10, 11). Nevertheless, it is favorable that its shape allows it to be used as a shelf.

It is also clear that for a person skilled in the art it is possible to carry out other modifications of the present invention; for example, to get a better aesthetic result, you can conveniently use a plastic or glass shelf with the “internal evaporator” (5) on the underside of the shelf. Thus, the advantage of energy conservation offered by a larger evaporation area relative to the prior art can be preserved, but the bearing surface can be improved both from an aesthetic and technical point of view: in fact, food products will not rely directly on the evaporator, but on an easily cleaned shelf.

Claims (13)

1. A cooling device (1) of a two-door type, comprising
cooling system
a chamber (2) for fresh foods, and
a chamber (3) for frozen food products, the cooling system comprising at least two evaporators (5, 14, 31, 32), wherein the evaporator cooling the chamber for frozen food products encompasses said chamber for frozen food products, characterized in that at least one section (5) of the evaporator (14, 31) cooling the chamber (3) for frozen food passes inside the chamber (3) for frozen food. 2. A cooling device (1) according to claim 1, characterized in that the chamber (3) for frozen food products has a volume of less than 60 l. 3. The cooling device (1) according to claim 1, characterized in that the chamber (3) for frozen food products has a volume of less than 30% of the volume of the chamber (2) for fresh food products. 4. The cooling device (1) according to claim 1, characterized in that the chamber (3) for frozen food products is of such a size that it makes it possible to insert a separation shelf (4) for placing food products. 5. The cooling device (1) according to claim 1, characterized in that the chamber (3) for frozen food products is of such a size that it makes it possible to insert only one separation shelf (4). 6. The cooling device (1) according to claim 5, characterized in that the height of the spaces (12, 13) defined by the dividing shelf (4) inside the chamber (3) for frozen food products is such as to enable the placement of food products, in particular, not less than 10 cm. 7. The cooling device (1) according to one of claims 4 to 6, characterized in that the shelf (4) is formed only by the section (5) of the evaporator (31) passing inside the cell (3) for frozen food products. 8. The cooling device (1) according to one of claims 4-6, characterized in that the shelf (4) has a bearing surface for food products, on the lower side of which there is an evaporator section (5) (31) passing inside the chamber (3 ) for frozen foods. 9. The cooling device (1) according to claim 8, characterized in that the supporting surface for food products is made of plastic material. 10. The cooling device (1) according to claim 8, characterized in that the supporting surface for food products is made of glass. 11. A cooling device (1) according to one of the preceding paragraphs, characterized in that the cooling system comprises means for cooling the chamber (3) for frozen food products irrespective of the chamber (2) for fresh food products. 12. A cooling device (1) according to claim 11, characterized in that the cooling means comprises an electromagnetic valve (34) and two capillaries (35, 36) connected to two chambers (2, 3) of the cooling device (1). 13. A cooling device (1) according to claim 12, characterized in that the electromagnetic valve (34) is controlled by an electronic temperature switch (40) and provides hydraulic switching between the two capillaries (35, 36).

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