EP2739495A1

EP2739495A1 - Desorber for device for air conditioning by absorption, comprising a housing with a cover

Info

Publication number: EP2739495A1
Application number: EP12738111.9A
Authority: EP
Inventors: Emmanuel Boudard; Florian Kervarec; Werner Zimmermann; Peter Binneberg
Original assignee: Webasto SE; Peugeot Citroen Automobiles SA
Current assignee: Webasto SE; PSA Automobiles SA
Priority date: 2011-08-03
Filing date: 2012-07-20
Publication date: 2014-06-11
Also published as: FR2978817A1; WO2013017438A1; FR2978817B1

Abstract

The invention relates to a desorber (100) for a device for air conditioning by absorption, especially for a motor vehicle, comprising a housing (110) and a heat exchanger received in the housing (110), a plurality of conduits (14, 15, 20, 71, 72) enabling the inflow and outflow of fluids into and out of the housing (110) and the heat exchanger. According to the invention, the housing (110) has an opening that is blocked by a cover (111) through which conduits (14, 15, 20, 71, 72) pass, said conduits being secured to the cover (111).

Description

DESORBEUR FOR ABSORPTION AIR CONDITIONING DEVICE COMPRISING A COVER

The present invention relates to desorber for air conditioning device by absorption.

It also relates to an absorption air conditioning device, especially for a motor vehicle, comprising such a desorber, and a motor vehicle equipped with this air conditioning device by absorption.

Among the existing air conditioning devices, there are known air conditioning devices by absorption, based on the principle of the absorption of a refrigerant fluid, in gaseous form, by an absorbent fluid. Unlike conventional mechanical compression air-conditioning devices, these non-mechanical absorption air-conditioning devices have few moving parts, which reduces noise and vibration, simplifies maintenance, and improves reliability and durability. of the device.

We have already sought to improve the performance of air conditioning devices by absorption to be able to implement them easily and reliably in vehicles. Such air conditioning devices still need to be improved to be implemented effectively in motor vehicles.

Thus, the volume of existing absorption air conditioning devices remains relatively large, and it is necessary to reduce it to effectively adapt such a system in the reduced space of a vehicle. Moreover, it is necessary to minimize the cost of the elements of these air conditioning devices. For this, it is necessary to simplify these elements to the maximum.

The object of the present invention is therefore to provide an absorption air conditioning device adapted to motor vehicles, which is improved in its operation with respect to known air conditioning or absorption cooling devices of the prior art.

In particular, the object of the present invention is to provide such an absorption air conditioning device that allows to offer the same performance with a reduced volume compared to the devices of the prior art.

Another object of the present invention is to provide such an absorption air conditioning device, which is simple in design and whose implementation requires inexpensive technological means.

[001 0] These objectives, as well as others which will appear more clearly later, are achieved by a desorber for an air conditioning device by absorption, especially for a motor vehicle, comprising a housing and a heat exchanger housed in the housing , a plurality of conduits for the entry and exit of fluids in the casing and in the heat exchanger, the casing having, according to the invention, an opening which is closed by a cover traversed by said ducts, which are secured of the lid.

[001 1] Advantageously, the lid and the fluid inlet and outlet ducts are made of the same material. According to a preferred embodiment of the invention, the lid and the fluid inlet and outlet ducts are made of aluminum.

Advantageously, at least one of the ducts is fixed to the lid by welding.

Advantageously, the heat exchanger is secured to the lid.

[001 5] Preferably, the ducts protrude on the outer face of the lid According to an advantageous embodiment, the cover and the heat exchanger are made of the same type of material, and the heat exchanger is fixed by welding to the inner face of the cover.

[001 7] Advantageously, the cover is shaped to ensure the distribution of heat transfer fluid in the exchanger.

[001 8] Advantageously, the housing is made of plastic material.

[001 9] According to a preferred embodiment, the cover is fixed to the housing by screwing. Thus, it can be dismountable for maintenance operations. According to another possible embodiment, the cover (1 1 1) is fixed to the housing (100) by a crimping. This closure is then final.

Preferably, the ducts comprise at least heat transfer fluid inlet and outlet ducts in the heat exchanger; an inlet conduit for mixing absorbent solution and refrigerant solution; a refrigerant solution vapor outlet duct; an outlet duct of absorbent solution.

The present invention also relates to an air conditioning device for absorption, in particular for a motor vehicle, comprising a desorber as described above. The present invention also relates to a motor vehicle comprising such an air conditioning device by absorption.

Other objects, advantages and features of the invention will appear in the following description of a preferred embodiment, not limiting the object and scope of the present patent application, accompanied by drawings in which :

• Figure 1 shows schematically the principle of operation of an air conditioning device by absorption; • Figure 2 shows schematically the functional circuit of an air conditioning device by absorption;

• Figure 3 shows, schematically, the desorber of an air conditioning device by absorption; FIG. 4 is a perspective view of a desorber according to one embodiment of the invention;

FIG. 5 is a perspective view of the casing of the desorber of FIG. 4;

FIG. 6 is a perspective view of the elements of the desorber of FIG. 4 without the housing.

An absorption air conditioning device uses a double fluid circuit, one carrying a refrigerant fluid, for example water, and the other an absorbent fluid, for example a lithium bromide salt solution. (LiBr). These two fluids are miscible, and part of the circuits is common to both circuits and carries a mixture of coolant and absorbent fluids.

Figure 1 shows schematically the constituent elements and the operating principle of an air conditioning device by absorption. It comprises an element in which the desorption is carried out, designated "desorber" 100 in the rest of the text, a condenser 200, an evaporator 300 and an absorber 400.

The desorber 100 and the absorber 400 are filled with a mixture of at least two miscible substances formed by the coolant and the absorbent fluid. This mixture is combined in the absorber 400, in which the absorbing fluid absorbs the refrigerant under vapor phase.

The cooling fluid and the absorbing fluid have sufficiently different evaporation pressures so that, when the mixture is heated in the desorber 100, the refrigerant, more volatile, evaporates, allowing the separation of the two fluids. The heat necessary for this separation (contribution illustrated schematically by the arrow A) can advantageously be provided to the desorber by the engine coolant of the vehicle. The refrigerant in the form of steam is then fed through the pipe 20 in the condenser 200 to be condensed by the cooling action of the outside air (cooling contribution schematically illustrated by the arrow B).

The coolant in the liquid phase is then fed through the pipe 10 to the evaporator 300. The cold produced during the evaporation of this refrigerant fluid is transmitted to the passenger compartment of the vehicle (not shown), as schematically illustrated. by the arrow C. To this end, there is provided a pump 310 and a fan heater 320, which are connected to the evaporator 300 through the pipes 1 1, 12 and 13. The coolant vapor that comes out of the Evaporator 300 is fed into absorber 400 through conduit 21 which is formed by the shell of the absorber / evaporator assembly. The absorbent fluid, which has been cooled by external air in the saline solution circuit (cooling supply schematically illustrated by the arrow D), then absorbs this water vapor to reform the mixture.

The saline solution circuit is formed by a pump 410 and a radiator 420, which are connected to the absorber 400 by the pipes 16, 17, 18 and 19. The absorber 400 is connected to the desorber 100 through the pipes. 14, 15 and 16. [0033] FIG. 2 shows the functional circuit of an absorption air conditioning to which the present invention can be applied. By way of non-limiting example, it is an absorption machine that uses the LiBr-water pair (lithium bromide as absorbent fluid and water as coolant). Elements of the circuit identical or similar to elements of Figure 1 are designated, most often, by the same reference numeral. The references 100 and 200 respectively denote the desorber and the coolant condenser. References 320 and 420 respectively designate the coolant heater and the radiator of the absorbent fluid.

The references 310 and 410 respectively denote the refrigerant circuit pump and the pump of the absorbent fluid circuit. References 350 and 450 respectively denote the refrigerant reserve and the absorbent fluid reserve. The references 62 and 63 designate check valves, and the reference 20 designates the pipe bringing the water vapor of the desorber 100 to the condenser 200.

The reference 500 designates an assembly that combines the absorber and the evaporator of the air conditioning device by absorption. In this evaporator / absorber assembly, traversed by a flow of refrigerant fluid and an absorbent fluid flow, a part of the refrigerant fluid is evaporated, and this evaporation reaction, endothermic, has the effect of cooling the flow of refrigerant remaining. The vapor produced is directly absorbed by the flow of absorbent fluid. Moreover, the heat produced by the exothermic absorption reaction is removed by the flow of absorbent fluid circulating in the block.

FIG. 3 represents, in a schematic manner, the desorber 100. This desorber 100 consists of a casing 1 10 in which an inlet 14 is opened for the mixture of absorbent fluid and refrigerant, an outlet 15 for the absorbent fluid, and a pipe 20 for discharging the refrigerant in the form of steam, leading to the condenser 200.

A heat exchanger 7 traversed by a hot fluid, for example the coolant from the engine of the vehicle, provides heat to the desorber 100. Thus, the mixture of absorbent fluid and refrigerant arriving through the inlet 14 is heated in contact with the exchanger 7, which causes evaporation of the refrigerant. After this evaporation, the absorbent fluid is recovered at the bottom of the casing 1 10 and out of the desorber 100 through the outlet 15. This operation is the desorption.

The housing 1 10, which must be sealed vis-à-vis the outside, can be made of plastic material for reasons of cost and weight. It surrounds the heat exchanger made of aluminum that can be painted or protected against corrosion, and is crossed by several aluminum ducts for the entry and exit of fluids in the housing and in the heat exchanger. Due to the difference in material between this housing on the one hand and the ducts and the heat exchanger on the other hand, the attachment of the exchanger in the housing and the sealing of the housing at the holes allowing the passage ducts is made difficult.

To avoid this difficulty, it is provided according to the invention to group on a housing cover the passage of the different ducts. Figures 4 to 6 show a desorber according to one embodiment of the invention. This desorber comprises a housing 1 having one of its open faces, which makes it possible to insert the various elements of the desorber shown in FIG. 6. This casing January 1, shown in FIG. 5, has a simple shape and is is crossed by no conduit. It can therefore easily be made of molded plastic material without the need for rework, and its cost is low for mass application.

The opening of this housing 1 10 is closed, for the use of the desorber, by a lid 1 1 1. This cover 1 1 has at its periphery holes 1 12 for fixing it by screw on the opening of the housing 1 10, which has corresponding holes. A seal placed between the casing 1 10 and the lid January 1 can, in a conventional and reliable way, seal the assembly.

This cover 1 10 is traversed by all the conduits for the entry and exit of fluids in the housing and in the heat exchanger. Thus, it is crossed by a conduit 14 supply solution mixture refrigerant and absorbent solution, which is connected to the system 141 for dispensing this mixture on the exchanger 7, through a conduit 15 for discharging the absorbent solution, through a conduit 20 for evacuation of the gas formed by the evaporation of the cooling solution. It is also traversed by two ducts 71 and 72 of the inlet and outlet of the coolant circulating in the heat exchanger 7, for example engine coolant. These two ducts 71 and 72 are connected to a distribution box ensuring the circulation of the coolant circulating in the tubes of the heat exchanger 7. On the outer face of the lid 1 1 1, the ducts 14, 15, 71 and 72 are tube portions forming aluminum connection tips. The duct 20, on the other hand, is in the form of a one-piece cylindrical portion with the cover 11 forming a connecting end. Grouping duct passages on the lid 1 1 1 allows to promote a good compactness of the air conditioning system.

Advantageously, the cover is made of aluminum, as the conduits that pass through it. Thus, it is possible to weld the conduits 14, 15, 71 and 72 to the lid January 1, which ensures a good seal thereof. The invention thus avoids the delicate implementation of a seal between the metal conduits and the plastic housing. The risk of leakage is thus reduced, and the reliability of the desorber is increased.

The use of aluminum for the manufacture of the lid 1 1 is made possible for a reasonable cost by the grouping of the ducts on the same side of the housing. This grouping makes it possible to limit the use of aluminum to only one of the faces of the casing, and thus to limit the costs associated with the material and the necessary machining thereof.

The cover 1 1 can be machined or molded and resumed machining, it can easily be adapted to receive the various sensors, including pressure, temperature and level, which must be reported on the housing by clipping or screwing . Similarly, it can easily support valves, for example for emptying, filling or evacuating the desorber.

In addition, the heat exchanger 7 can also be fixed easily and effectively, by welding, on the inner face of the lid 1 1 1. This heat exchanger 7 and the lid 11 1 thus form the assembly shown in Figure 6, which can easily be inserted into the housing 1 10 and fixed thereto.

Advantageously, the inner face of this cover may be shaped so as to fulfill the functions of distribution box of the exchanger, to ensure the distribution of heat transfer fluid in the exchanger 7. This configuration avoids the use of a separate distribution box, and thus generates a saving and a saving of mass of the system.

Claims

claims

Desorber (100) for an absorption air-conditioning device, particularly for a motor vehicle, comprising a housing (110) and a heat exchanger (7) housed in the housing (110), a plurality of ducts (14, 15, 20, 71, 72) for the entry and exit of fluids in the housing (110) and in the heat exchanger (7), characterized in that the housing (110) has an opening which is closed by a cover (111) traversed by said ducts (14, 15, 20, 71, 72), which are integral with the lid (111).

2. Desorber according to claim 1, characterized in that the cover (111) and the conduits (14, 15, 20, 71, 72) are made of the same material.

3. Desorber according to claim 2, characterized in that the cover (111) and the ducts (14, 15, 20, 71, 72) are made of aluminum.

4. Desorber according to any one of claims 1 to 3, characterized in that at least one of the ducts (14, 15, 20, 71, 72) is fixed to the lid (111) by welding.

5. Desorber according to any one of claims 1 to 4, characterized in that the heat exchanger (7) is integral with the lid (111).

6. Desorber according to claim 5, characterized in that the cover (111) and the heat exchanger (7) are made of the same material, and that the heat exchanger (7) is fixed by welding to the face inside the lid (111).

7. Desorber according to any one of claims 5 and 6, characterized in that the cover (111) is shaped to ensure the distribution of heat transfer fluid in the heat exchanger (7).

8. Desorber according to any one of claims 1 to 7, characterized in that the housing (100) is made of plastic material.

9. Desorber according to any one of claims 1 to 8, characterized in that the cover (1 1 1) is fixed to the housing (100) by screwing.

10. Desorber according to any one of claims 1 to 8, characterized in that the cover (1 1 1) is fixed to the housing (100) by crimping.

1 1. Desorber according to any one of claims 1 to 10, characterized in that the ducts comprise at least: - heat transfer fluid inlet and outlet ducts in the heat exchanger (71, 72);

an inlet duct for admixing absorbent solution and refrigerant solution (14);

a refrigerant solution vapor outlet duct (20); an absorbent solution outlet duct (15).

12. An absorption air conditioning device, especially for a motor vehicle, characterized in that it comprises a desorber (100) according to any one of claims 1 to 1 1.

13. Motor vehicle, characterized in that it comprises an absorption air conditioning device according to claim 12.