WO2014059500A1

WO2014059500A1 - Thermal transfer system for liquids by direct mean, and reservoir provided with direct thermal transfer system for liquid

Info

Publication number: WO2014059500A1
Application number: PCT/BR2013/000420
Authority: WO
Inventors: Gustavo Lazzaris De BONA; Dilso BUCHNER
Original assignee: Whirlpool S.A.
Priority date: 2012-10-16
Filing date: 2013-08-15
Publication date: 2014-04-24
Also published as: BR102012026490A2

Abstract

The present invention relates to a thermal transfer system for liquids by direct thermal transfer, said system comprising a reservoir (1) comprising at least one incorporated passage tubing (5) of thermal transfer medium of the thermal transfer system for liquid (4) and extending, in a built-in manner, along at least one wall (11) of the reservoir (1), and means of providing direct thermal transfer of the liquid stored inside the reservoir (1) without demanding a reduction of the internal area thereof of liquid storage.

Description

"THERMAL TRANSFER SYSTEM FOR LIQUIDS BY DIRECT MEAN, AND RESERVOIR PROVIDED WITH DIRECT THERMAL TRANSFER SYSTEM FOR LIQUID".

Field of the Invention

The present invention relates to a thermal transfer system (preferably cooling) for liquids, preferably water, made by means of direct thermal transfer in which the tank itself acts as evaporator. For this purpose, the tubes through which the thermal transfer system passes (for example, the cooling element) are incorporated into the wall itself of the liquid storage reservoir, thus conferring direct heating or cooling of the water stored inside. Therefore, the construction presented has technical and functional characteristics able to provide a different container structure having high heat performance in the thermal transfer of water, since the evaporator remains in direct contact with the water without, to that end, reducing the available water storage internal area, thus providing increased efficiency, practicality and economics when compared to similar existing systems.

Background of the Invention

As is known in the art, the manufacturers of water purifier equipment currently use, in the components intended for water storage, metal or plastic tanks around which there are positioned, externally, evaporators for cooling water. However, such a solution for cooling water presents a low performance, since between the evaporator and the fluid to be cooled it is located the reservoir wall and, moreover, the contact between the bodies is made linearly, what damages the heat exchange between the cooled gas and water, besides involving a complicated, therefore, expensive manufacturing process - an example of this embodiment is shown in document US 8,057,665.

Another solution was presented in document US 7,069,738, which describes a storage and cooling tank, in which the cooling element, which has a freezing point below 0 (zero) Celsius degree, passes along a fluid passage that is defined on the tank body wall and surrounded by an insulating material, in a system known as "skin evaporator". However, this solution still has the problem of constructive complexity and limited efficiency due to the existence of the tank wall between the fluid and the passage channel of the cooling gas.

Other manufacturers use the evaporator within the tank to enhance the heat exchange between the cooling element and the liquid, as shown, for example, in document KR937954. However, this positioning of the evaporator occupies a volume that would normally be filled by the fluid, which is intended to be stored and cooled, and therefore, this technique considerably reduces the useful volume of the tank. Another example of such application is found in document KR 20040093535, which discloses a cooling apparatus for water purifier which comprises a plate containing a plurality of micro channels corresponding to the cooling element passages inside, this system also presents a high manufacturing cost.

Additionally, there are manufacturers who use Peltier effect tanks to cool water which, however, also have a low yield. It must be remembered that in the known similar systems, it is necessary to apply a considerable power to promote the initial cooling of water in order to minimize the chance that the water considered as refrigerated is not provided, in the early stages of operation, in a virtually room temperature; further, the number of glasses of ice water which can be obtained in a single operation with the apparatus of the current state of the art presents some limitation.

Note, therefore, that the current state of the art lacks an effective, practical, versatile and economical solution to promote the rapid cooling of water, or analogously the heating thereof, especially with regard to the application in water purifiers / coolers in which the cooling process should be fast and optimized, minimizing the occurrence of loss of heat exchange between the cooling gas and the fluid, and which provides a productivity significantly higher than that obtained with the use of the similar known ones.

Objectives of the Invention

In view of the above exposed with respect to the prior art limitations, it is proposed a new concept of water thermal transfer system, which acts as a reservoir with direct thermal transfer system, similar to that used in refrigerators, but intended to the storage of water - which can be frozen or heated.

Therefore, one of the objectives of the present invention is to provide a thermal transfer system for water that provides to a temperature change rate of a greater volume of water in a time shorter than that achieved by the use of the known systems.

Thus, it is an objective of the present invention to provide a liquid storage tank which has a high yield, i.e. a high ratio between the thermal energy withdraw of the liquid stored and electrical energy spent to cool / heat the thermal transfer element, without occupying the useful internal volume of the tank by the passages of cooling / heating element.

Additionally, it is an objective of the present invention to provide a liquid storage tank that does not use complex manufacturing process, i.e. comprising a structure easy to manufacture and of simple and practical implementation.

It is yet another among the objectives of the invention, to disclose a thermal transfer system for liquids which results in a considerable increase in the number of glasses of cold / hot water which can be obtained when compared to the current systems.

Summary of the Invention

The above objectives are achieved by means of a thermal transfer system for liquids by direct means, said system comprising a reservoir for the liquid storage containing at least one liquid inlet, at least one liquid outlet and a thermal transfer system for liquid cooperating with the reservoir, said thermal transfer system for liquids comprising passage tubing of thermal transfer medium.

In one of the preferred embodiments of the invention, said system comprises at least one incorporated passage tubing of thermal transfer means of the thermal transfer system for liquid and extending, in a built-in manner, along at least one wall of the reservoir.

The invention comprises, in short, means to provide direct thermal transfer of the liquid stored inside the tank without requiring reduction of its liquid storage internal area.

Preferably, the at least one passage tubing of thermal transfer mean of the thermal transfer system for liquid extends helically along the inside of at least one vertical wall of the reservoir and, optionally, the at least one passage tubing of thermal transfer medium of the thermal transfer system for liquid extends along the bottom surface of the reservoir.

Also in a preferred embodiment, the direct thermal transfer system for liquids comprises a temperature control device of the NTC resistor type (Negative Temperature Coefficient).

Therefore, the suggested objectives are achieved, also, by means of a reservoir provided with direct thermal transfer system for liquid, comprising at least one liquid inlet, at least one liquid outlet and a thermal transfer system for liquid comprising passage tubing of thermal transfer medium, wherein that said reservoir comprises at least one incorporated passage tubing of thermal transfer medium of the thermal transfer system for liquid, in a built- in manner, along at least one wall of the reservoir.

Brief Description of the Drawings

The present invention will be described in detail based on the bellow indicated figures, in which:

Figure 1 illustrates a sectional view of a tank of the present technique in which the passages of cooling element are located in the outer region of the tank;

Figure 2 illustrates a sectional view of another tank of the current state of the art in which the passages of cooling element are located inside the tank, thereby reducing the useful internal volume of water storage;

Figure 3 illustrates a sectional view of one of the possible embodiments to the thermal transfer tank for liquid which is object of the present invention.

Detailed Description of the Invention

The object of the present invention will be described below in more detail, but in a merely exemplary character, and not limitative, since the thermal transfer system for liquids with a direct thermal transfer reservoir which is object of the present invention may comprise different details and structural and dimensional aspects without, thereby, departing from the scope of protection desired.

It should be explained that the description below emphasizes the embodiment intended to the cooling of liquids, but it is clear that the object of the present invention can be used both for cooling and for heating any liquid.

Thus, in a preferred embodiment, the present invention relates to an equipment comprising a preferably cylindrical reservoir 1 for the storage of water, said reservoir 1 comprising a liquid inlet 2 and outlet 3, both conventionally located in the upper part of the reservoir 1.

The water stored in the reservoir 1 aims to be, upon the user request, cooled, which is accomplished by the action of a cooling medium (usually cooled gas) that runs in the tubing 5 cooperating with the water stored inside the reservoir 1.

According to Figure 1 , it can be noted that the system known from the prior art basically comprises a reservoir 1 , a liquid inlet 2, a liquid outlet 3 and a plurality of passage tubing 5 of cooling element around the reservoir 1 , thus cooling the liquid contained inside it. These passage tubing 5 of cooling element are located next to the outer surface of the reservoir wall 11 , so that the contact between the plurality of tubing 5 and the reservoir 1 is made in line and intended to cause heat exchange between both, thus cooling the water stored in the reservoir 1.

As can be seen from Figure 1 , the contact area between the passage tubing 5 of cooling element and the outer wall 11 of the reservoir 1 is very small, and even if the format of the passages of cooling element is changed, the contact area between them would still be substantially small. Thus, the efficiency of the heat exchange between the cooling element and the liquid becomes low, since that the greater the distance between the cooling element and the liquid medium to be cooled, the greater will be the loss of heat exchange between the cooling element and the medium to be cooled and, consequently, the greater the thermal loss with the external environment.

In Figure 2, it is noted another technique already known of water cooling system, also comprising a reservoir 1 , a liquid inlet 2, a liquid outlet 3 and a plurality of passage tubing 5 of cooling element 5.

The main difference between the technique illustrated in Figure 2 and the technique illustrated in Figure 1 is that, in the technique of Figure 2, the plurality of passage tubing 5 of cooling element is located next to the internal surface of the wall 11 of the reservoir 1 , while in the technique of Figure 1 , the plurality of passage tubing 5 of cooling element is located next to the outer surface of said wall 11 .

Thus, with the solution of Figure 2, it is solved the problem related to the unwanted heat exchange with the external environment, since the entire contact area of the passage tubing 5 of cooling element is in direct contact with the liquid of the reservoir 1. However, as can be seen from Figure 2, part of the internal volume of the reservoir 1 is occupied by the passage tubing 5 of the cooling element, thereby reducing the useful internal volume thereof.

As for Figure 3, it illustrates a preferred embodiment of the object of the present invention. In this system, the plurality of passage tubing 5 of cooling element is located within, i.e. built-in in the side walls 1 1 of the reservoir 1 in a system known as "roll bond evaporator". Thus, it is solved the problem of the undesired heat exchange between the cooling element and the external environment, since the cooling element will act, on the one hand, directly on the fluid medium to be cooled and, on the other hand, in the side wall 11 of the reservoir 1 , so that the propagation of the temperature on the wall surface 11 will also assist in cooling the water stored in the reservoir 1.

Additionally, the problem of the loss of useful volume within the container is also solved, since, with the passage tubing 5 of cooling element positioned within the side wall 11 of the reservoir 1 , the internal volume thereof is not changed.

It should be explained that, in the preferred embodiment of the invention shown in Figure 3, there are shown tubing 5 arranged substantially parallel in the vertical wall 11 of the reservoir 1 , however it can be designed a single tubing 5 helically running through the wall 11 of the reservoir 1 , or even the existence of tubing 5 also built-in in the bottom or lower surface 12 of the reservoir 1 without thereby departing from scope of protection desired.

Preferably, the temperature control of the cooling element or thermal transfer medium will be accomplished through at least one NTC device (Negative Temperature Coefficient), basically comprising a resistor whose resistance depends on the temperature. This resistor, as the name suggests, has a negative temperature coefficient, i.e. as the NTC temperature increases, the resistance thereof decreases.

The insulation of the tank is preferably accomplished through the use of EPS (Expanded Polystyrene) around the tank, since the EPS is a product commonly used for insulation due to its characteristics of lightness, strength and resistance to aging.

It should be further emphasized that the solution of the present invention provides a significant reduction in the energy consumed to cool the same volume of water, since the cooling process is faster due to the direct contact of the evaporator with the fluid - which ends up by allowing, also, the withdraw of a greater number of glasses of cold water that can be performed in a given time interval.

Another novelty of the present invention refers to the temperature change rate, since the lowering rate of the temperature of a larger volume of water is possible on a time significantly shorter than that observed with similar known ones.

It is important to note that the above description is solely intended to describe in an exemplary way the preferred embodiments of the thermal transfer tank for liquid particularly used in water filters. So, as well understood by the skilled on the subject matter, there are possible numerous constructive modifications, variations and combinations of the elements that perform the same function in substantially the same way to achieve the same results, which are within the scope of protection defined by the appended claims.

Claims

1. Thermal transfer system for liquids by direct medium, said system comprising a reservoir (1 ) for the storage of liquid containing at least one liquid inlet (2), at least one liquid outlet (3) and a thermal transfer system (4) cooperating with the reservoir (1 ), said thermal transfer system (4) comprising passage tubing (5) of thermal transfer medium CHARACTERIZED in that it comprises:

- at least one incorporated passage tubing (5) of thermal transfer medium of the thermal transfer system for liquid (4) and extending, in a built-in manner, along at least one wall (1 1 ) of the reservoir (1 ), and

- means for providing direct thermal transfer of the liquid stored inside the reservoir

(1 ) without demanding a reduction of its internal storage area of liquid.

2. System, according to claim 1 , CHARACTERIZED in that the at least one passage tubing (5) of thermal transfer medium of the thermal transfer system for liquid (4) extends helically along the inside of at least one vertical wall (11 ) of the reservoir (1 ).

3. System, according to claims 1 and 2, CHARACTERIZED in that at least one passage tubing (5) of thermal transfer medium of the thermal transfer system for liquid (4) extends along the bottom surface (12) of the reservoir (1 ).

4. System, according to claim 1 , CHARACTERIZED in that said thermal transfer system for liquids comprises a temperature control device of the NTC resistor type (Negative Temperature Coefficient).

5. Reservoir provided with direct thermal transfer system for liquid, said reservoir (1 ) comprising at least one liquid inlet (2), at least one liquid outlet (3) and a thermal transfer system for liquid (4) comprising incorporated passage tubing ( 5 ) of thermal transfer medium CHARACTERIZED in that said reservoir comprises at least one passage tubing (5) of thermal transfer medium of the thermal transfer system for liquid (4), in a built-in manner, along at least one wall (11 ) of the reservoir (1 ).