Abstract:
The invention relates to a condenser receiver adapted to receive and house a fluid used in a cold loop of an air-conditioning system, said condenser receiver comprising an outer wall and an inner wall. The inner wall defines an inner space for housing a fluid, while the outer wall is provided on its outer surface with a plurality of ribs that increase the heat exchange between the fluid contained in the inner space and the ambient air outside the condenser receiver.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a condenser cylinder used for an air-conditioning circuit, for example the air-conditioning circuit of an automobile. More specifically, the present invention relates to a condenser cylinder that makes it possible to improve the process of cooling a liquid used in the cold loop of the air-conditioning system. 
       STATE OF THE ART 
       [0002]    The use of an air-conditioning system is known in the automotive industry. An air-conditioning system makes it possible to significantly improve comfort in an automobile interior. The air-conditioning system may be used in order to regulate the temperature of the automobile interior and in order to dehydrate the ambient air inside said automobile. The air-conditioning system may therefore be used in particular with the aim of preventing condensation on the insides of the windows of an automobile. 
         [0003]    In a cold loop which is generally used in an air-conditioning system, the stages of evaporation, compression, condensation and expansion take place one after another by using a suitable fluid such as a fluid of the R134 or 1234YF type. After the condensation stage, the fluid is maintained in a liquid state inside a reservoir. This reservoir may be integrated into a condenser or may stand alone and be connected to the outlet of said condenser. 
         [0004]    When the fluid is condensed in the condenser, said fluid circulates at the saturation temperature of said fluid towards a reservoir such as a condenser cylinder. A condenser cylinder has the function of separating the liquid and gas phases in a fluid in order to allow only the fluid to exit in its liquid state. At the same time, the condenser cylinder may be used with the aim of sub-cooling the fluid, i.e. of reducing the temperature of the fluid used in the cold loop to below the saturation temperature corresponding to the defined condensation pressure. 
         [0005]    This process of sub-cooling is a process which is known in the prior art for a system of cooling by means of compression. The technical effect of this process lies in improving the efficiency of said system of cooling by means of compression, by virtue of a modification of the enthalpy of the fluid used in the cold loop. 
         [0006]    According to the prior art, the condenser cylinder has a first function of maintaining the fluid used in the cold loop. Additional functionality consists, for example, in absorbing humidity by virtue of the presence of a material such as a suitable gel. The condenser cylinder may also serve to filter the fluid present in the cold loop, thus preventing particles having a larger size than a set threshold value from circulating within the air-conditioning system. 
         [0007]    According to the prior art, the function of sub-cooling the fluid present within a condenser cylinder is not optimal. 
         [0008]    There appears to be a need for modifications enabling the function of sub-cooling the fluid present within a condenser cylinder to be improved in order to optimize the efficiency of the air-conditioning system. 
       OBJECTIVE OF THE INVENTION 
       [0009]    The present invention relates to a condenser cylinder adapted to receive and contain a fluid used in a cold loop of an air-conditioning system, the condenser cylinder comprising an external wall and an internal wall, said internal wall defining an interior space for containing a fluid, said external wall being provided on an external surface thereof with a plurality of ribs enabling an increase in heat exchange between the fluid contained in the interior space and the ambient air present outside said condenser cylinder. 
         [0010]    According to a preferred mode of embodiment of the present invention, the external wall of said condenser cylinder has a thickness of between 0.8 and 4 mm. 
         [0011]    According to a preferred mode of embodiment of the present invention, each rib from the plurality of ribs has a height of between 0.2 and 10 mm in the radial direction of said condenser cylinder. 
         [0012]    According to a preferred mode of embodiment of the present invention, each rib from the plurality of ribs has a thickness of between 0.2 and 10 mm. 
         [0013]    According to a preferred mode of embodiment of the present invention, the external wall of said condenser cylinder is obtained by means of an extrusion process. 
         [0014]    According to a preferred mode of embodiment of the present invention, said condenser cylinder is obtained by means of a brazing process. 
         [0015]    According to a preferred mode of embodiment of the present invention, the condenser cylinder has an internal wall and an external wall positioned at a set distance from one another in order to delimit an intermediate space provided between said internal wall and said external wall, said intermediate space comprising a component adapted to store and release a set quantity of heat. 
         [0016]    According to a preferred mode of embodiment of the present invention, the component adapted to store and release a set amount of heat comprises a phase change material (PCM). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The aims, objective and features of the present invention and also the advantages thereof will become clearer on reading the following description of preferred modes of embodiment of a condenser cylinder according to the invention, given with reference to the drawings in which: 
           [0018]      FIG. 1  shows a view in perspective of a condenser cylinder according to the invention, 
           [0019]      FIG. 2  shows in detail the upper end of the condenser cylinder according to  FIG. 1 , 
           [0020]      FIG. 3  shows, schematically and as a view in cross section, the different elements present inside the condenser cylinder according to  FIGS. 1 and 2 , and 
           [0021]      FIG. 4  shows a detail of the exterior of the condenser cylinder according to  FIGS. 1 and 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The following detailed description aims to disclose the invention in a sufficiently clear and full manner, in particular with the aid of examples, but should in no case be regarded as limiting the scope of protection to the particular mode of embodiment and examples given hereinafter. 
         [0023]      FIG. 1  shows a view in perspective of a condenser cylinder  10  according to the present invention, said cylinder being usable in combination with a condenser and being adapted to hold therein a quantity of fluid present in a cold loop such as a liquid of the R134 or 1234YF type. 
         [0024]    In order to receive the fluid and to allow the fluid to escape, the condenser cylinder  10  is provided with an inlet  20  and an outlet  30  at a lower end thereof. 
         [0025]      FIG. 2  shows a detail of the upper end of the condenser cylinder  10  according to the invention. 
         [0026]    As shown in  FIG. 2 , the condenser cylinder  10  comprises an external wall  12  and an internal wall  13 . The external wall  12  of the condenser cylinder  10  is covered with a set number of ribs  21  extending in a longitudinal direction on said external surface of the external wall  12 . The set formed by the ribs  21  present on the outside of the condenser cylinder  10  has the effect of increasing the surface area suitable for heat exchange with the ambient air. In other words, heat exchange with the ambient air around the condenser cylinder  10  is thus improved in comparison with heat exchange performed in accordance with the prior art with condenser cylinders having a smooth external surface. 
         [0027]      FIG. 3  shows, schematically and as a view in cross section, the condenser cylinder  10  according to  FIGS. 1 and 2 .  FIG. 3  shows the different ribs  21  visible on the outside of the external wall  12  of the condenser cylinder  10 . The external wall  12  and the internal wall  13  define an intermediate space  14  situated between the external wall  12  and the interior wall  13 . According to the invention, said intermediate space  14  may be used to contain a set quantity of phase change material (PCM). The volume available on the inside of the internal wall  13  defines an interior space  15  in order to receive and maintain a quantity of fluid used in the cold loop. 
         [0028]    The presence of a set quantity of phase change material (PCM) has several technical effects. Specifically, the PCM is a material adapted to store and release a set quantity of heat. The presence of this material between the external wall  12  and the internal wall  13  of the condenser cylinder  10  may serve to stabilize the temperature of the liquid present in the interior space  15 . This stability has a first positive technical effect on the efficiency of the condensing system in which the condenser cylinder  10  is used. 
         [0029]    As shown in  FIG. 2 , the external wall  12  extends above the end of the internal wall  13 , close to the upper end of the condenser cylinder  10 . This particular feature provides the opportunity to close off the upper end of the condenser cylinder  10  with the aid of a single cap covering all of the different spaces available inside the condenser cylinder  10 . 
         [0030]    As shown in  FIG. 3 , the condenser cylinder  10  has an external diameter D 2 . The useful volume for maintaining fluid present inside the cold loop is defined using the internal diameter D 1 . The value of D 1  is between 25 and 65 mm. The value of D 2  is such that the ratio of the internal diameter D 1  to the external diameter D 2  preferably lies between 0 and 50%, depending on the use of the condenser cylinder  10  and stabilization of the fluid contained inside the interior space  15 . 
         [0031]    In  FIG. 4 , the reference symbols “a”, “b”, “c” and “d” denote different characteristics in relation to the height, width and thickness, respectively, of a rib  21 , and also to the gap between two ribs  21  and the depth of the external wall  12 . These different dimensions “a”, “b”, “c” and “d” are defined according to the use to the use of the condenser cylinder  10  on which the different ribs  21  are present. 
         [0032]    The value of the height “a” of the different ribs  21 , according to  FIG. 4 , thus preferably lies in a range of values between 0 and 10 mm. The value of the width “b” of the ribs  21 , according to  FIG. 4 , preferably lies in a range of values between 0 and 10 mm. The value of the thickness “c” preferably lies in a range of values between 0.8 and 4 mm, preferably between 1 and 3 mm. The value of the distance “d” between two adjacent ribs preferably lies in a range of values between 0.2 and 10 mm. 
         [0033]    According to a preferred mode of embodiment of the present invention, the different walls as shown in cross section in  FIG. 3  are obtained by means of an extrusion process. Except for the different connections intended for the condenser cylinder  10 , said condenser cylinder  10  and the different caps making it possible to close off the ends are obtained by means of a single process. 
         [0034]    According to a preferred mode of embodiment of the present invention, the upper end of the condenser cylinder  10  as shown in  FIG. 2  and the lower end of the condenser cylinder  10  may be closed off by means of a cap, such as a plastic cap in combination with rings in the shape of a letter “O”. Alternatively, the upper and lower ends may be closed off by means of aluminum caps in combination with rings in the shape of a letter “O”. As a further alternative, the upper and lower ends may be closed off by means of a brazing process during which the caps are brazed to the ends of the condenser cylinder  10 . 
         [0035]    According to the present invention, the PCM used to fill the intermediate space  14  may be a PCM for which the phase change temperature is between 45 and 55° C. 
         [0036]    According to a mode of embodiment of the present invention, the PCM may be of the liquid type or composite type comprising graphite enabling improved thermal conductivity of the PCM.