WO2007147280A2

WO2007147280A2 - Adsorption-type cold generation device and retaining valve mounted on this device

Info

Publication number: WO2007147280A2
Application number: PCT/CH2007/000307
Authority: WO
Inventors: Catherine Hildbrand; Julien Mayor
Original assignee: Heig-Vd
Priority date: 2006-06-23
Filing date: 2007-06-20
Publication date: 2007-12-27
Also published as: WO2007147280A3; WO2007147280B1; EP2032883A2; WO2007147280A8

Abstract

The invention relates to an absorption-type cold generation device, especially a refrigeration apparatus or an air-conditioning installation, and to the retaining valve with which this device is equipped. The device comprises an insulated refrigerating chamber containing an evaporator, an absorber, which picks up heat from a hot source and is connected to the evaporator by means of a duct, a condenser, which is mounted on this duct between the absorber and the evaporator of the refrigerating chamber, and a retaining valve connected to the duct between the condenser and the evaporator. This retaining valve (20) has a base (21) that constitutes an annular spherical seat (24) for an ultra-lightweight spherical ball (25) that can move inside a buffer tank (26) mounted on the upper face of the base (21). A capillary tube winding (30) is placed in this base (21) and communicates with the buffer tank (26) when the ball (25) is pressed on its annular seat (24).

Description

COLD GENERATOR DEVICE WITH ADSORPTION AND RETENTION VALVE MOUNTED ON THIS DEVICE

TECHNICAL FIELD The present invention relates to an adsorption cold generating device, in particular a refrigerating apparatus or an air conditioning installation, said device comprising, on the one hand, an insulated refrigeration chamber in which an evaporator is housed and, on the other hand an external adsorber which captures the heat of a hot source, a duct which connects said adsorber to said evaporator of the refrigerating enclosure, a condenser which is mounted on said duct at the outlet of said adsorber and a check valve which is mounted on said duct between said condenser and said evaporator.

It also relates to a check valve mounted on this adsorption cold generating device, in particular a refrigerating apparatus or an air conditioning installation, said device comprising, on the one hand, an insulated refrigerating chamber in which an evaporator is housed and, d on the other hand, an external adsorber which captures the heat of a hot source, a duct which connects said adsorber to said evaporator of the refrigerating enclosure, a condenser which is mounted on said duct at the outlet of said adsorber and said check valve which is mounted on said conduit between said condenser and said evaporator.

Prior art

Adsorption cold generation is designed on the basis of a physical phenomenon, adsorption, which occurs when an equilibrium is established between a gas and a solid. The concentration of gas molecules is greater near the surface of the solid than in the gas phase. Thus, in any solid, the surface atoms are subject to unbalanced forces of attraction, perpendicular to the surface, which creates an imbalance. The equilibrium of these forces is partially restored by the adsorption of the gaseous molecules. The bodies used as adsorbents are bodies which have a very large external surface, such as activated aluminas, activated carbons, silica gels and zeolites. The choice of adsorbent is based on the desired temperature at the evaporator and the temperature available at a hot source, which may be a solar collector for example. The other part of the pair, the adsorbate, must meet two essential conditions, namely to have a high latent heat of evaporation and to consist of easily adsorbable small molecules. Fluids possessing these characteristics include water, ammonia, methanol and carbon dioxide. In addition to these two physical conditions, it is necessary to take into account the nature of the fluid and in particular its dangerousness, including its flammability and toxicity. As examples, the following couples were used, activated carbon and methanol, silica gel and water or zeolite and water. The use of these pairs of substances imposes a mean vacuum level of the order of 10 ^-3 mbar in order to minimize the presence of incondensable gases that can block the passage of the adsorbate vapors.

The refrigeration cycle operates intermittently and cold is produced only during the re-adsorption phase. Cold generators of this type have four main elements, namely:

an adsorber which is the part containing the adsorbent which is heated by the hot source with the effect of the desorption of the adsorbate,

a condenser which is the part serving to condense the adsorbate vapors desorbed in the adsorber, an insulated refrigerating chamber which constitutes the useful part of the cold generator and which contains an evaporator comprising the adsorbate in liquid and solid form, and

- A check valve that separates the high pressure part of the low pressure part of the cold generation system.

Currently, this type of cold generator is equipped with a manual valve, which requires a human presence, or an automatic valve controlled by motorized means and which require a power source and an electronic control of regulation.

Different types of check valves or valves are known from the prior art.

In particular US Pat. No. 4,788,828 describes a flow control device in the context of a refrigeration circuit integrated in a compression type refrigerator. This adjusting member comprises a bellows whose expansion or contraction depending on the temperature causes the modification of the passage section of the refrigeration fluid. The valve of this adjustment member is linked to the bellows and is therefore not free.

The European publication EP 1 519 128 also relates to a flow control member in a compression refrigerator device. This adjustment member makes it possible to play on the phase change and the pressure variations related to the temperature differences in order to obtain a variable cooling cycle in power. The valve ball is connected to a compression spring and is also not free.

The international publication WO 01/06183 describes a regulator for two different charges for a CO ₂ refrigerator device in which the gas contained in the membranes is condensed or not as a function of the temperature or pressure of the CO ₂ . The valves of this regulator are linked to bellows.

All these members have major drawbacks and are intended to equip compression refrigeration systems which are completely different from an adsorption refrigeration device according to the invention. In addition, they are unsatisfactory for use in places without nearby sources of energy or organized technical services. Presentation of the invention

The present invention therefore proposes to provide an adsorption cold generator device equipped with a check valve, which does not require any local energy source, which blocks the passage of gases during the desorption phase, which allows to leave pass the liquid during this same phase and let the adsorbate vapors in the evaporator-adsorber direction.

This adsorption cold generator device as defined in the preamble is characterized in that said check valve comprises a body which constitutes a buffer tank extended by at least one tubular base, provided at its upper end with at least one seat annular, said buffer tank housing at least one movable spherical ball arranged to press against said at least one annular seat for sealingly closing said buffer tank, and said at least one base containing at least one capillary tube winding communicating with said buffer tank for allowing the evacuation of the condensate contained in said buffer tank, when said at least one ball is pressed against said at least one annular seat.

According to a preferred embodiment, said at least one spherical ball of said check valve is made of an ultralight material. It is advantageously made of cellulose, such as table tennis balls.

Advantageously, said at least one capillary tube winding connects the lower part of the circuit, namely the conduit which is in communication with the evaporator of the insulated refrigerating chamber, with the upper part of the circuit, namely the buffer tank. said check valve which is itself in direct communication with the condenser and the adsorber.

Said buffer tank of said check valve is preferably closed at its upper end by a closure element arranged to cooperate with a endpiece which resists a connection to a vacuum chamber for the connection of said valve to the conduit.

According to a preferred form of construction, said at least one base is provided at its lower end with a tip which resists connection to a vacuum chamber for connection of said check valve to the conduit.

The check valve as defined by the preamble equipping an adsorption cold generation device according to the invention is characterized in that it comprises a body which constitutes a buffer reservoir extended by at least one tubular base, provided with its upper end of at least one annular seat, said buffer tank housing at least one movable spherical ball arranged to press against said at least one annular seat in order to seal said buffer tank, and said at least one base containing at least one capillary tube winding communicating with said buffer tank to allow evacuation of the condensate contained in said buffer tank, when said at least one ball is plated on said at least one annular seat.

Said at least one spherical ball is preferably made of an ultralight material which may advantageously be cellulose.

Said at least one capillary tube winding advantageously connects the lower part of the circuit, namely the conduit which is in communication with the evaporator of the insulated refrigerating enclosure, with the upper part of the circuit, namely the buffer tank which is - even in direct communication with the condenser and the adsorber.

The buffer tank is preferably closed at its upper end by a closure element arranged to cooperate with a nozzle which is resistant to connection to a vacuum chamber for connection of said valve to the conduit.

Said at least one base is, according to a preferred embodiment, provided at its lower end with a nozzle which resists a connection to a vacuum chamber for the connection of said check valve to the conduit.

Brief description of the drawings

The present invention and its advantages will be better understood on reading the detailed description of a preferred embodiment of the invention and with reference to the appended drawings given by way of non-limiting indication, in which:

FIG. 1 is a schematic view showing a cold generating device, in particular a solar thermal adsorption refrigerator, according to the invention,

FIG. 2 represents an exploded perspective view of a preferred embodiment of the check valve according to the invention, and

FIG. 3 represents an elevational view of the assembled check valve of FIG. 2.

Best way to realize the invention

With reference to FIG. 1, a cold generator device according to the invention, in particular an adsorption solar thermal refrigerator 10 essentially comprises an isolated refrigerating enclosure 11 containing an evaporator 12 and the ice storage which is formed in said evaporator, said enclosure forming the utilitarian part of the refrigerator of the invention, an adsorber 13 which captures the heat of a hot source and which may be a solar collector, said adsorber being connected to the evaporator 12 by means of a duct 14, and a condenser 15 which is mounted on said duct 14 between a check valve 20 and the adsorber 13, the check valve 20 being disposed on the duct 14, between the evaporator 12 of the refrigerating chamber 11 and the condenser 15. The adsorber 13 is the element which contains the adsorbent which is heated by the hot source, formed by the solar radiation in the present case, with the effect of the desorption of the adsorbate . In a known manner, it can be of the tube type or of the flat type. The condenser 15 is the element which serves to condense the adsorbed vapors desorbed in the adsorber 13.

The check valve 20 of the invention, which is self-contained, does not require any independent power source, operating means or electronic control, and which equips the refrigerator 10, is designed to operate in a vacuum circuit. With reference to FIGS. 2 and 3, this retaining valve 20 comprises, in the embodiment described, a base 21 comprising a cylindrical upper part 22 extending downwards by a frustoconical part whose lower part is extended by an end piece. connection 23. The cylindrical portion 22 is provided with a spherical central bore forming an annular seat 24 for a spherical ball 25 consisting for example of an ultralight cellulose ball, such as a table tennis ball, acting as a valve . On this base 21 is mounted a buffer reservoir 26 formed of a cylindrical tube open at both ends, whose outer diameter is equal to the outer diameter of the cylindrical upper portion 22 of the base 21 and whose inner diameter is greater than the The upper end of this buffer tank 26 is provided with a flange 27a arranged to cooperate with a closure element 27b, composed of a pierced lid corresponding to the ISO-KF standard and provided with a central bore arranged to receive a connecting piece 29. The closure between the flange 27a and the closure member 27b is provided by a clamp / seal assembly 28. The two connecting pieces 23 and 29 are provided for connection respectively at the lower part or cold part of the refrigeration circuit, which is in communication with the evaporator 12 and at the upper part or hot part of the circuit , which is in direct communication with the condenser 15. To allow these connections to the conduit 14 of the refrigerator 10, the end pieces 23 and 29 are provided to withstand a connection to a vacuum enclosure corresponding to ISO KF.

The connection end 23 of the base 21 is also arranged to house a winding of a metal capillary tube 30 disposed under the seat of the ball 25 and laterally fixed, in a manner known per se, to the inner wall of said endpiece. 23. This winding 30 connects the cold part of the circuit, namely the portion of the conduit 14 which is in communication with the evaporator 12, with the hot part of the circuit, namely the portion of the conduit 14 which is in communication with the condenser 15 through the buffer tank 26. For this purpose, one end 31 of the tube opens into the upper face of the base 21, next to the seat of the ball 25, while the other end 32 opens directly in the conduit 14 connected to the valve 20 by the connecting end 23. The capillary tube used preferably has an inside diameter of about 1 mm and the length of the winding is of the order of 2 meters.

The refrigerator 10 equipped with such a self-contained check valve operates as follows:

In the morning, before the condensation phase, and therefore before the reheating of the adsorber 13 due to solar radiation, the shutter constituted by the spherical ball 25 isolates the upper part of the circuit, consisting of the adsorber 13 and the condenser 15, of the evaporator 12, to enable it to rise in pressure and temperature. At this time the check valve 20 does not allow the passage of steam because the ball 25 is pressed against its spherical seat and the capillary tube has too much resistance to the passage of steam. The first phase of operation corresponds to the isosteric heating during which the solar radiation heats the adsorber 13 so that the vapor pressure and the temperature increase in the system.

At the end of the morning, when the radiant energy of the sun has heated the adsorber 13 and the upper part of the circuit 14 has reached the saturation pressure of the adsorbate corresponding to the temperature of the condenser 15, ie the external temperature, the condensation of the vapors begins and the condensates stored in the buffer tank 26 flow towards the evaporator 12 via the capillary tube 30 which leaves them pass to the evaporator 12. The ball 25 remains pressed against its spherical seat 24 and prevents the passage of steam.

In the evening, when the sunlight decreases, the adsorbent of the adsorber 13 cools isosterically and the pressure of the upper part decreases to become lower than the pressure prevailing in the lower part containing the evaporator 12. At this time there is no more condensate in the buffer reservoir 26 of the check valve 20 and, by the effect of the pressure prevailing in the lower part, the ball 25 rises by letting the vapor produced by the evaporation of the liquid in the evaporator 12 and producing the desired cooling effect. This vapor returns to the adsorber 13 via the buffer tank 26. In practice, during this cooling, the adsorbent is physically unbalanced and will recharge by adsorbing the vapor contained in the system. When the temperature in the evaporator 12 reaches the solidification point of the adsorbate, there is formation of ice which allows the insulated refrigerating chamber 11 to remain at a low temperature for the next day and several days, which allows, if necessary, maintain a refrigerated enclosure even under adverse weather conditions.

The presence of a fully self-contained check valve in the cold production circuit is particularly important since it allows the refrigerator to operate independently of any source of electrical power. The absence of moving parts allows it to function almost without wear. The essential constraint is the maintenance of the vacuum in the circuit.

The use of the self-contained valve described is not limited to a solar refrigerator. It can be used in any device with a vacuum circuit.

Claims

1. A device for generating adsorption cold, in particular a refrigerating apparatus or an air-conditioning installation, said device (10) comprising, on the one hand, an insulated refrigerating chamber (11) in which an evaporator (12) is housed and, on the other hand, an external adsorber (13) which captures the heat of a hot source, a duct (14) which connects said adsorber (13) to said evaporator (12) of the refrigerating chamber (11), a condenser (15) which is mounted on said conduit (14) at the outlet of said adsorber (13) and a check valve (20) which is mounted on said conduit (14) between said condenser

(15) and said evaporator (12), characterized in that said check valve (20) comprises a body which constitutes a buffer tank (26) extended by at least one base (21) of tubular shape, provided at its upper end at least one annular seat (24), said buffer tank (26) housing at least one movable spherical ball (25) arranged to press against said at least one annular seat (24) for sealing said reservoir buffer (26), and said at least one base (21) containing at least one capillary tube winding (30) communicating with said buffer tank (26) to allow evacuation of the condensate contained in said buffer tank when said at least one ball (25) is pressed against said at least one annular seat (24).

2. Cold generating device according to claim 1, characterized in that said at least one spherical ball (25) of said check valve (20) is made of an ultralight material.

3. cold generating device according to claim 2, characterized in that said lightweight material is cellulose.

4. cold generating device according to claim 1, characterized in that said at least one capillary tube winding (30) connects the lower part of the circuit, namely the conduit (14) which is in communication with the evaporator (12) of the insulated refrigerating chamber (11), with the upper part of the circuit, namely the buffer tank (26) of said check valve (20) which is itself in direct communication with the condenser (15) and the adsorber (13).

5. Cold generating device according to claim 1, characterized in that the buffer tank (26) of said check valve (20) is closed at its upper end by a closure member (28) arranged to cooperate with a nozzle (29). ) which resists a connection to a vacuum enclosure for connection of said valve (20) to the conduit (14).

6. cold generating device according to claim 1, characterized in that said at least one base (21) is provided at its lower end with a tip (23) which resists a connection to a vacuum chamber for connection said check valve (20) to the conduit (14).

Retention valve for an adsorption cold generating device according to any one of the preceding claims, said device comprising, on the one hand, an insulated refrigerating chamber (11) in which an evaporator (12) is housed and, on the other hand, an external adsorber (13) which captures the heat of a hot source, a duct (14) which connects said adsorber (13) to said evaporator (12) of the refrigerating chamber (11), a condenser ( 15) which is mounted on said duct (14) at the outlet of said adsorber (13) and a check valve (20) which is mounted on said duct (14) between said condenser (15) and said evaporator (12), characterized in that it comprises a body which constitutes a buffer reservoir (26) extended by at least one base (21) of tubular shape, provided at its upper end with at least one annular seat (24), said buffer reservoir (26) ) housing at least one spherical ball (25) movable arranged to press on said at least one annular seat (24) for sealing said buffer tank (26), and said at least one base (21) containing at least one capillary tube winding (30) communicating with said buffer tank (26) to allow the evacuation of the condensate contained in said buffer tank, when said at least one ball (25) is pressed against said at least one annular seat (24).

8. Check valve according to claim 7, characterized in that said at least one spherical ball (25) is made of an ultralight material.

9. Restraint valve according to claim 7, characterized in that said lightweight material is cellulose.

Retention valve according to Claim 7, characterized in that the at least one capillary tube winding (30) connects the lower part of the circuit, namely the duct (14) which is in communication with the evaporator (12). the insulated refrigerating chamber (11), with the upper part of the circuit, namely the buffer tank (26) which is itself in direct communication with the condenser (15) and the adsorber (13).

11. Check valve according to claim 7, characterized in that the buffer tank (26) is closed at its upper end by a closure member (28) arranged to cooperate with a tip (29) which resists a connection to a vacuum enclosure for connecting said valve (20) to the conduit (14).

12. Restraining valve according to claim 7, characterized in that said at least one base (21) is provided at its lower end with a tip (23) which resists a connection to a vacuum chamber for the connection of said check valve (20) at the conduit (14).