WO2010076762A2

WO2010076762A2 - Device for refrigerating a body and method for cooling a body or object

Info

Publication number: WO2010076762A2
Application number: PCT/IB2009/055977
Authority: WO
Inventors: Jose Antonio Serrano Molina
Original assignee: Criogenius, S.L.
Priority date: 2008-12-31
Filing date: 2009-12-29
Publication date: 2010-07-08
Also published as: ES2352991B1; ES2352991A1; WO2010076762A3

Abstract

The device comprises a chamber (3) in which a body or object to be cooled is arranged, an enclosure (6) which comprises a cryogenic refrigerating fluid, a pipe (5) for conveying air from said chamber (3) to said enclosure (6) inside which said air is cooled by means of indirect contact with the fluid, means (10) for forced circulation of air through said pipe (5) for cooling said chamber (3), and means (9, 11, 20) for controlling said forced-air circulation means depending on the temperature of said chamber (3), and is characterized in that said enclosure (6) comprises a tank (4) for storing said fluid and said tank (4) comprises an element (8) for transmitting heat to the fluid by means of contact and in that said pipe (5) comprises a section (5a), inside said enclosure (6), arranged so as to be associated with said transmission element (8) of the tank (4), so that the heat of the air in said pipe (5) is transmitted by means of direct or indirect contact with said element (8) to the fluid stored in the tank (4).

Description

DEVICE FOR REFRIGERATING A BODY AND PROCEDURE FOR

COOL A BODY OR OBJECT

The present invention relates to a cooling device comprising a cryogenic fluid, and to a method for cooling a body or object by indirect contact with said cryogenic cooling fluid.

BACKGROUND OF THE INVENTION

Cooling devices are known that comprise a cryogenic fluid for cooling bodies or objects by contact.

Some of the cooling devices have a cooling chamber whose air is cooled by direct or indirect contact with said cryogenic fluid. These cooling devices are commonly used to keep biological material, such as embryos, at very low temperatures. European Patent EP1793185 describes one of said devices in which air is circulated through a duct from the chamber in which the body or object to be cooled to a second chamber in which the cryogenic fluid is located. The exchange of heat between the air and the fluid is carried out in the second chamber through a surface of the conduit itself that is in direct contact with the fluid. The generated cold air is conducted again to the chamber in which the material is located, through the same duct. A control circuit monitors the temperature of the first chamber, and controls the speed of the circulating air based on the temperature that is desired to have in the cooling chamber.

The described cooling device is suitable for freezing and conserving materials to cryogenic temperatures However, it is not suitable for simply cooling materials or, for example, freezing materials at temperatures higher than cryogenic, such as those commonly used in household freezers.

DESCRIPTION OF THE INVENTION

The objective of the present invention is to solve the aforementioned drawbacks, developing a cooling device and a method for cooling bodies or objects that has the advantages described below.

In accordance with this objective, according to a first aspect of the present invention, a cooling device is provided comprising a chamber in which a body or object to be cooled is arranged, an enclosure comprising a cryogenic cooling fluid, a conduit for conducting air from said chamber towards said enclosure in which said air is cooled by indirect contact with the fluid, forced air circulation means through said duct to cool said chamber, and control means of said forced air circulation means in function of the temperature of said chamber. The device is characterized by the fact that said enclosure comprises a reservoir for storing said fluid, and said reservoir, an element for transmitting heat contact to the fluid, and for the fact that said conduit comprises a section, inside said enclosure, arranged associated with said reservoir transmission element, so that the heat of the air in said duct is transmitted by direct or indirect contact with said element to the fluid stored in the reservoir. According to a second aspect of the present invention, a method is provided for cooling a body or object by indirect contact with a cryogenic fluid comprising the steps of; a) arranging the body or object to be cooled in a chamber, and in an enclosure, said cryogenic fluid, b) forcing, through a conduit, the circulation of air from said chamber to said enclosure in which said air is cooled by indirect contact with said fluid, c) cooling said chamber by means of the cold air of said duct, until the temperature of said chamber reaches a predetermined value, and which is characterized by the fact that said enclosure comprises a reservoir for storing said fluid, and said reservoir, an element for transmitting heat to said fluid, and by the fact that step b) comprises the step of cooling the air in the duct by direct or indirect contact with said element.

In the device and method of the present invention, the heat exchange between the air and the fluid is carried out through a heat transfer element associated with the reservoir in which the fluid is stored, and not through the surface of the air duct itself as is the case with prior art devices. Thanks to this, the air temperature of the cooling chamber can be controlled much more precisely, since said element can be designed with the appropriate material, shape and size to transmit a predetermined amount of heat to the fluid. On the other hand, since said element, and not the air duct, the source of cold air that is in contact with the fluid, it is much easier to control the entry of cold air into the cooling chamber, which positively affects the temperature control of said chamber. Thanks to this, the claimed device can provide temperatures similar to those provided by a domestic refrigerator or freezer, but with the advantage that it is practically autonomous, since it requires a very low energy consumption.

According to the first aspect, the present invention relates to a device in which, preferably, said tank is a cryogenic tank whose wall comprises said heat transfer element. The cryogenic tank allows the fluid to be stored under pressure, providing autonomy to the device, exceeding 4 days for an approximate fluid load of four liters.

According to a preferred embodiment of the device, said transmission element comprises a part whose outer surface is in contact with a surface of said conduit, so that the heat of the air of said conduit is transmitted by contact with said conduit to said element, and of this to the reservoir fluid.

In this way, the amount of heat transmitted to the fluid can be easily modulated, varying the size and material of said piece.

Advantageously, the surfaces of said conduit and said element part comprise means of mutual engagement. This ensures efficient contact for heat transmission.

Preferably, said heat transfer element comprises a second part that extends inside the tank to contact the fluid. In this way, the contact of the heat transfer element with the fluid stored in the tank is always ensured.

Again preferably, said device comprises means for closing or opening the air inlet and outlet of said chamber through said duct. In this way, the cooling chamber is not exposed to cold air associated with the duct, so that its temperature is prevented from varying by contact with said cold air. Thanks to this, a more accurate control of the chamber temperature is ensured. Advantageously, said means for closing or opening the air inlet and outlet are capable of thermally insulating the air in said chamber from the air in said duct.

According to the same preferred embodiment, said device comprises an outer casing, and a watertight wall, inside said casing, which separates said chamber from the enclosure in which the reservoir is located.

In this way, the atmosphere surrounding the cooling chamber is completely isolated from the heat transfer zone in which the cold source is located, which further facilitates temperature control. On the other hand, the watertight wall allows that the atmosphere of the enclosure in which the deposit is located can be treated to eliminate moisture, thus avoiding the formation of ice.

Preferably, according to the same preferred embodiment said device comprises means for heating the air of said chamber. In this way, the temperature of the chamber can be corrected effectively, if it falls more than desired, so it is very easy to maintain the temperature of the chamber within a pre-established temperature range that can preferably range between 25 ⁰ C and - 4O ⁰ C.

As previously mentioned, unlike the devices of the prior art, the use of the claimed device is not limited only to the field of cryogenic conservation, but is useful for application in multiple fields and environments; food preservation, vaccines, medicines, organs, industrial products diverse, etc ...

Advantageously, said heating means comprise an air inlet coming from the outside of the device into said chamber, and said device, means for opening or closing the outside air inlet depending on the temperature of said air and the chamber air.

In this way, the outside air can be used to heat the chamber, so energy is saved, allowing the device to be even more autonomous. Optionally, said heating means comprise an electrical or chemical resistance to heat the chamber air.

Preferably, said means of forced air circulation through said duct comprise a fan disposed inside said chamber to allow homogenization of the air and to facilitate the entry of said outside air when necessary.

According to the second aspect, the present invention relates to a method for cooling a body or object which, preferably, comprises the step of heating the air of said chamber by forcing the entry of outside air into the device to maintain the temperature of said chamber within a default range of values.

In this way, the chamber's atmosphere can be heated in a very efficient and economical way, to keep its temperature within preset values which, preferably, will be between 25 ⁰ C and -4O ⁰ C.

According to one embodiment, the method comprises the step of measuring the temperature of said outside air and the step of heating the air in said chamber by means of electrical or chemical resistances, if the temperature of said outside air is below a preset value.

In the present invention, cryogenic fluid will preferably be understood as any liquid whose point of Boiling is below -90 ⁰ C at an absolute pressure of 101,325 kPa.

Advantageously, said cryogenic fluid will be liquid nitrogen, since this fluid is safe and economical.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of how much has been exposed, some drawings are attached in which, schematically and only by way of non-limiting example, a practical case of realization is represented.

In said drawings, Figure 1 shows a cross section of an embodiment of the device. Figure 2 shows a perspective view of the duct through which cold air circulates. Figure 3 shows a perspective view of the exterior of the tank and the heat transfer element disposed on the wall of said tank. Figure 4 shows a detail of a part of the heat transmission element of Figure 3. Figure 5 shows an interior view of the tank in which the heat transmission element arranged on the wall is seen. Figure 6 is a schematic drawing of the cooling and heating circuit of the device.

DESCRIPTION OF A PREFERRED EMBODIMENT

As can be seen in Figure 1, the refrigerator device 1 of the present invention is a portable device consisting of a housing 2 inside which a cooling chamber 3, a reservoir 4 for storing cryogenic fluid, and a conduit are housed. 5 to conduct air from said chamber 3 to the sealed enclosure 6 in which the cooling fluid with which said air is cooled is located. In the embodiment described the fluid used is liquid nitrogen, however, any other type of cryogenic fluid could be used.

In the described embodiment, the wall 7 of the tank 4 has a heat transfer element 8 which is arranged associated with the air duct 5, so that the heat of the air flowing through said duct 5 is transmitted to the fluid stored in the deposit 4, by direct or indirect contact with said element 8.

Thus, unlike what happens in the devices of the state of the art, in the device 1 of the present invention the heat exchange between the air and the fluid is carried out through a transmission element 8 specially designed for this end, and not through the air duct 5 itself that is in contact with the fluid. Thus, as discussed above, it is much easier to control the temperature of the chamber 3, since it is said element 8, and not said conduit 5, that is in contact with the fluid.

The cold air that is generated in the heat exchange zone of the element 8 is recirculated to the chamber 3, through the same duct 5, until said chamber 3 reaches a predetermined temperature. For this, the device 1 is provided with a control board and a plurality of probes or sensors 9 that measure the internal temperature of the chamber 3 and the temperature of the external air of the device 1. Depending on the desired temperature and the temperature internal temperature of the chamber 3 measured by the sensor, the control board determines the operating time and the speed of the fan 10 that forces the circulation of the air inside the duct 5.

In the described embodiment, the device 1 is provided with insulating electro-gates 11 which have the function of opening or closing the air inlet and outlet of the chamber 3 through said duct 5. Said gates 11 always close that the temperature of the chamber 3 is within the chosen parameters preventing the temperature of the chamber 3 from varying by contact with the cold air of the duct 5.

As can be seen in Figure 1, the heat transfer element 8 consists of a first piece 12 whose outer surface 13 is in contact with a wall 14 of the duct 5, and a second piece 15, which extends into the inside the tank 4 to contact the fluid. The size and material of the pieces 12, 15 of the element 8 can be varied depending on the amount of heat to be transmitted. In the embodiment described, said parts are metallic. Figure 2 represents the conduit 5 of the device 1, in which the section 5a which is associated with the transmission element 8 is seen inside the sealed enclosure 6.

In the described embodiment, the wall 14 of the duct 5, and the outer surface 13 of the part 12 of the element 8, are configured to fit together, thus ensuring an effective transmission of heat by contact. Figure 4 shows a detail of the connection between said piece 12 and the wall 14 of the duct 5.

Figures 3 and 5 represent perspective views of the reservoir 4 in which the cryogenic fluid is stored. In the described embodiment, said reservoir 4 is a cryogenic reservoir 4 that houses said fluid under pressure, providing autonomy to the device longer than 3 days. However, any other type of deposit would be valid for manufacturing the device 1. For example, said deposit 4 could be constituted by the walls of the housing 2 itself and the watertight wall 16 that determine the enclosure 6 of the device 1.

The tank 4 can be easily recharged through a loading tube 17 of the device 1. In this sense, a pressure probe or sensor 18 arranged at the base of the tank 4, allows the weight to be calculated and indicated, by means of the control plate , the fluid level.

As mentioned, the device 1 provides for the heating of the air in the chamber 3 by means of outside air, or resistors 19 arranged in the same chamber 3. For this, as can be seen schematically in Figure 6, it has provided, next to the air inlet coming from the duct 5, an air inlet coming from the outside that is also protected by an insulating electric gate 20. In the same air inlet the resistors 19 have been mounted.

When it is necessary to heat the chamber air, the control board of the device 1 opens the passage of the air inlet 20 coming from the outside and drives the fan 10 to introduce said air into the chamber 3. The temperature of the outside air is controlled by means of a sensor 9a, so that, if the temperature is lower than that desired in chamber 3, then said control board activates the resistors 19.

The operation of the device of the present invention is described below.

The start of the use session is carried out with the start-up of the control system that allows to see on a screen, the battery level, the level of refrigerant fluid existing in the tank 4, as well as the temperature inside the chamber 3. Once it is verified that there is sufficient energy and cooling fluid, the control system asks about the working temperature that is desired to have in the cooling chamber 3 and the range of working temperatures (accuracy level) that is desired. Once both parameters have been entered, the control board starts the session by giving the orders for the opening of the gates 11 of the air duct 5, and the actuation of the fan 10. Then, the air in the chamber 3 begins to circulate through the duct 5 until the section 5a where said air cools as it passes through the heat exchange zone, constituted by the wall 14 of the duct 5 itself and the transmission element 8, which is in contact with the fluid in the reservoir 4. The chamber air 3 is progressively cooled by the cold air of the duct 5 until the temperature of said chamber 3 reaches the preset value. At this time the gates 11 of the duct 5 are closed, preventing the cold air of the duct 5 from varying by contact the temperature of the chamber 3.

Once the desired temperature has been achieved, the control system remains on alert according to the preset temperature and operating mode (accuracy level), to reactivate the cooling circuit if necessary, or, if necessary, activate the heating circuit. The same control system also remains on alert to warn, by means of acoustic signals if necessary, about the reserve levels of both the battery and the fluid.

In case it was necessary to activate the air heating circuit of the chamber 3, the gate 20 would be opened and the fan drive 10 to intermittently introduce outside air until the temperature of the chamber 3 It was the desired one. If the outside air were below the desired temperature, the resistors 19 would be activated.

As mentioned in the description of the invention, the claimed device 1 provides temperatures similar to those provided by a domestic refrigerator or freezer, but with the advantage that it is portable and practically autonomous, since it can work with rechargeable batteries already which only has the electrical consumption needed by the sensors 9, the fan 10 and the control elements.

Although a specific embodiment of the present invention has been described and represented, it is clear that the person skilled in the art will be able to introduce variants and modifications, or replace the details with other technically equivalent ones, without departing from the scope of protection defined by the claims. attached.

For example, although in the described embodiment the heat of the air flowing through the conduit 5 is transmitted by direct contact with the element 8 to the fluid stored in the tank, it would also be possible for the heat of the air to be transmitted to the element 8 by direct contact of said air with said element 8. For this, in this case, element 8 would be associated with the section of duct 5a by means of some part of element 8 that would penetrate inside the duct 5a to contact the air.

Claims

1. Cooling device comprising a chamber (3) in which a body or object to be cooled is arranged, an enclosure (6) comprising a cryogenic refrigerant fluid, a conduit (5) to conduct air from said chamber (3) towards said enclosure (6) in which said air is cooled by indirect contact with the fluid, means (10) of forced air circulation through said duct (5) to cool said chamber (3), and means (9, 11 , 20) for controlling said means of forced air circulation as a function of the temperature of said chamber (3), characterized in that said enclosure (6) comprises a reservoir (4) for storing said fluid, and said reservoir (4), an element (8) for transmitting heat contact to the fluid, and by the fact that said conduit (5) comprises a section (5a), inside said enclosure (6), arranged associated with said element (8) of transmission of the tank (4), so that the heat of the air from said duct (5) is transmitted or by direct or indirect contact with said element (8) to the fluid stored in the tank (4).

2. Device according to claim 1, wherein said transmission element (8) comprises a part

(12) whose outer surface (13) is in contact with a surface (14) of said conduit (5), so that the heat of the air of said conduit (5) is transmitted by contact to said element (8), and from this to the reservoir fluid (4).

3. Device according to claim 2, wherein the surfaces (13.15) of said conduit (5) and said part (12) of the element (8) comprise means of mutual engagement.

Device according to claims 2 or 3, wherein said heat transfer element (8) comprises a second piece (15) that extends inside the tank (4) to contact the fluid.

Device according to claim 1, comprising means (11) for closing or opening the air inlet and outlet of said chamber (3) through said duct (5).

Device according to claim 5, wherein said means (11) for closing or opening the air inlet and outlet are capable of thermally isolating the air in said chamber from the air in said duct.

Device according to claim 1, comprising an outer housing (2), and a sealed wall (16), inside said housing (2), which separates said chamber (3) from the enclosure (6) in which the tank (4) is found.

Device according to claim 1, comprising means (19, 20) for heating the air of said chamber (3).

Device according to claim 8, wherein said heating means comprise an outside air inlet, and said device (1), means (20) for opening or closing the outside air inlet, depending on the temperature of said air and chamber air (3).

10. Device according to claims 8 or 9, wherein said heating means comprise a electrical or chemical resistance (19) to heat the chamber air (3).

Device according to any of the preceding claims, wherein said forced air circulation means comprise a fan (10) disposed inside said chamber (3).

12. Procedure for cooling a body or object by indirect contact with a cryogenic fluid comprising the steps of; a) arranging the body or object to be cooled in a chamber (3), and in an enclosure (6), said cryogenic fluid, b) forcing, through a duct (5), the air circulation of said chamber (3 ) towards said enclosure (6) in which said air is cooled by indirect contact with said fluid, c) cooling said chamber (3) forcing the circulation of cold air from said duct (5), until the air temperature of said chamber (3) reaches a predetermined value, characterized in that said enclosure (6) comprises a reservoir (4) for storing said fluid, and said reservoir (4), an element (8) for transmitting heat contact to said fluid, and by the fact that step b) comprises the step of cooling the air in the duct (5) by direct or indirect contact with said element (8).

13. The method of claim 12, comprising the step of heating the air in said chamber (3) forcing the outside air inlet to maintain the temperature of said chamber (3) within a predetermined range of values.

14. The method according to claim 13, in said range of temperature values is between 25 ⁰ C and -4O ⁰ C.

15. A method or device according to any of the preceding claims, wherein said cryogenic fluid is liquid nitrogen.