VEHICULAR/AUTOMOTIVE COMBINATION COMPRESSOR AND CONDENSER UNIT

Abstract: The present invention relates to a combination compressor and condenser unit for use in automotive refrigeration/air conditioning systems. A compressor sub-unit (205) compresses refrigerant and a condenser sub-unit (202) performs a condensing operation on the refrigerant exiting the compressor. The condenser and compressor sub-units are mounted together to form an integrated unit (210) such that the refrigerant exits the compressor sub-unit (205) directly into the condenser sub-unit (202) across an interface including a gasket or other seal positioned between the sub units.

Description: Vehicular/Automotive Combination Compressor and Condenser Unit The present invention relates to a combination compressor and condenser unit for use in automotive refrigeration/air conditioning systems. According to a first aspect, the present invention provides an integrated automotive compressor/condenser unit comprising; (i) a compressor sub-unit stage arranged to compress refrigerant; and, (ii) a condenser sub-unit stage arranged to perform a condensing operation on the refrigerant exiting the compressor stage; wherein the condenser and compressor sub-units are mounted together to form an integrated unit and such that the refrigerant exits the compressor sub-unit stage directly into the condenser sub-unit stage across an interface comprising or including a gasket or seal means positioned between the sub units . Desirably the compressor stage includes a compressor stage body and the condenser stage includes a condenser stage body, the respective compressor stage body and condenser stage bodies being substantially contiguous with one another. Extensive refrigerant conduits or lines extending from one body to another are therefore not required. The refrigerant outlet port of the compressor stage it preferably co-aligned with the refrigerant inlet port of the condenser stage, preferably arranged to be contiguous with or immediately adjacent the refrigerant inlet port of the condenser stage . A seal or gasket may be interposed between the compressor stage and condenser stage. The condenser stage and compressor stage together comprise a single, self-supporting unit connected to, or formed integrally with, one another. The condenser stage audcompressor stage are thereby secured or held fast to one another. Where the stages are formed of initially separate sub units they may be structurally joined by mechanical means (such as bolting) or bonded together to form an integrated unitary assembly. The condenser stage preferably comprises: (i) a refrigerant flowpath; and, (ii) a liquid coolant flowpath in thermal heat transfer contact with the refrigerant flowpath. The condenser stage refrigerant flowpath beneficially comprises a first gallery system, and the liquid coolant flowpath a second gallery system. The first and second gallery systems are substantially sealed from one another. The condenser stage gallery systems are preferably defined by a plurality of stacked elements. The stacked elements are preferably nested shell and/or plate elements spaced to define the respective gallery systems. The invention will now be further described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a schematic view of a ' prior art refrigeration/air conditioning system; Figure 2 is a schematic view of a refrigeration/air conditioning system according to the invention; Figure 3 is a schematic side view of a unit according to the invention suitable for use in the system of figure 2 ; Figures 4 and 5 are perspective views of embodiments of stacking elements which may be ' used to make up the condenser stage of the unit of figure 3; Figure 6 is sectional view through a part of the condenser stage of the unit of figure 3 ; and Figure 7 is a schematic perspective view of the condenser stage of the unit of Figure 6. Referring to the drawings and initially to figure 1, there is shown an exemplary basic refrigeration/air conditioning system 101. The system 101 includes a refrigerant flowpath including an air cooled condenser 102, an expansion valve 103, an evaporator 104 and a compressor 105. A receiver- drier 106 is included in the refrigerant circuit between the condenser 102 and expansion valve 103 as is known in the art. Referring to the system 201 embodying the invention in figure 2, the same basic components are present comprising a compressor stage/condenser stage 210, expansion valve 203 and evaporator 204. A receiver-drier 206 is also present in the refrigerant circuit . In the embodiment shown in figure 2, the compressor and condenser are provided as a combined unit 210 which is manufactured as sub units assembled together. The condenser stage 202 is liquid (typically water) cooled. The construction of the water cooled condenser stage and the unitary assembly of the compressor stage and condenser stages will be described in greater detail hereafter. The condenser stage 202 comprises a series of nested stacked metallic shells 2 (Figures 4 and 5) , bonded to form the structure shown in Figures 6 and 7. Typically the shells 2 are aluminium and brazed in a single shot brazing operation to form a unitary structure. The stacked shells 2, define therebetween first and second sealed gallery systems in alternating layers. A "water side" gallery system communicating between a water inlet 5 communicating through a top plate 6 of the condenser and a water outlet 4. The second gallery system also defined by the shells 2 comprises a ' "refrigerant side" gallery system communicating between a refrigerant inlet 19 (via a gasket seal 25 interposed between the compressor and condenser stages 205, 202) and a refrigerant outlet 7. As will be described in detail hereafter, the gallery system is arranged such that the stacked arrangement has "water side (coolant) " galleries alternating with "refrigerant side" galleries. Adjacently arranged shell plates 2 are rotated through 180 degrees with respect to one another such that downwardly projecting rims of apertures 10a, 10b abut upwardly projecting rims of apertures 9a, 9b to define the gallery systems and water and refrigerant x cores' communicating betweeri respective galleries in each system. A turbulator plate 13 is sandwiched between adjacently stacked shell plates 2. The turbulator plate 13 may comprise a pressed metallic component having a plurality of- apertured ridge formations extending generally transversely to the major face of the turbulator plate, the ridges including a multiplicity of apertures permitting fluid (water coolant or refrigerant) flow -.throughout the gallery. The upper surface of the turbulator plate 13 is contiguous with the underside of an overlaid shell 2. The underside of turbulator plate 13 is bonded to the planar surface of an underlaid shell 2. The turbulator plates 13 are nested in respective plain shells 2 during assembly. The side walls 21 of shells 2 are inclined upwardly and outwardly from the major. face of the shell element 2. The sidewalls extend upwardly beyond the top surface of turbulator plate 13 permitting the nesting of an overlaying shell 2 within the side wall 21. As an alternative to using a separate turbulator plate, the shells 2 may be formed to include turbulating projections which also serve to separate the adjacent shell elements. A dimpled shell as shown for example in figure 5 may be used. Dimpled shell 2 includes a spanning portion 23 terminating in an outwardly and upwardly inclined peripheral wall 21. Spanning portion 23 is provided with an array of dimpled projections 15, projecting upwardly in the corresponding direction to peripheral wall 21. On its 'obverse side spanning portion 23 is provided with a series of dimpled depressions (resulting from the deformation of plate 13 during the forming of the dimples 15). Apertures 9a, 9b, 10a, 10b in dimpled shell 2 correspond to the apertures in the plain shell element 2 described above. - -- The fluids may flow in the same direction or opposing directions. The fluid paths may be single pass, two pass or multi-pass through the condenser. Heat is transferred from the higher temperature refrigerant, through the thin walls of the shell elements 2, to the cooling liquid. The fitted turbulator or dimpled shells, break up the laminar flow of the fluids to increase efficiency by mixing local hot and cold regions in each fluid. The turbulator 13 and dimples 15 also provide a secondary heat transfer surface, which conduct heat directly out of the refrigerant, and transfer it into the cooling liquid. The form of the turbulator 13 and dimples 15 are tuned to suit the refrigerant and cooling liquid properties, in order to maximise fluid mixing and minimise fluid pressure drop through the condenser. The heat transfer from the refrigerant to- the cooling liquid is normally sufficient to produce a change of state in the refrigerant, transforming it from a high pressure high temperature gaseous phase into a high pressure lower temperature liquid phase. As described above the refrigerant passes into a refrigerant outlet orifice of condenser stage 202 directly from the compressor stage 205 via inlet orifice 19 and through a corresponding aperture in the gasket seal 25. The compressor includes a corresponding refrigerant outlet orifice which is co-aligned with the condenser inlet orifice 19 and gasket seal 25 aperture. The respective orifices and gasket seal paths are pressed together to define the refrigerant flow path. The compressor stage 205 may be. conventional in most respects but is mechanically connected to the condenser stage 202 (for example by bolting or other securing) to provide the integrated condenser/compressor unit assembly 210. The refrigerant output from the compressor stage 205 is via a compressor stage outlet port co-aligned with the inlet port 19 of the condenser stage 202. Outlet port 7 may be connected to a refrigerant hose in a conventional manner to supply refrigerant to the receiver drier 206 and expansion valve 203. The integrated compressor/condenser unit of the present invention is particularly suited to replace a conventional air cooled condenser and compressor in a refrigeration or air conditioning system where performance requirements are high and spatial considerations important (such as for example for vehicle based systems) . For a given heat transfer performance requirement, it can be shown that a liquid cooled refrigerant condenser provides a more compact heat exchanger solution than an air cooled condenser of equivalent performance. The invention avoids the requirement for expensive high pressure refrigerant hoses and fittings between the compressor and the condenser. The high cost refrigerant hoses are replaced by ! the low cost water (coolant) hoses. The volume of refrigerant required in the refrigeration/air conditioning system is also reduced compared to a comparable conventional system. Additionally the spatial efficiency of the compressor/condenser arrangement is improved compared with a comparable conventional system. The smaller more compact configuration permits the condenser to be packaged in locations that optimise hose routings, where an adequate current of cooling air is not available to an air-cooled condenser. For example, typical systems using air cooled condensers have the condenser positioned in front of the vehicle engine coolant radiator. This blocks airflow into the radiator and is therefor detrimental to other aspects of the vehicle performance or engine component configuration . The use of a liquid cooled refrigerant condenser stage has the following additional advantages: - The cooling liquid will generally have a considerably higher density (p) and specific heat capacity (Cp) than air. This gives the potential for a much greater heat transfer from the refrigerant in a smaller more compact condenser. For example, if water is used as the cooling medium, the comparison is: Air - p = 1.177kgm- 3 , Cp = 1.0049kJkg- 1 K Jl @ 27°C Water - p = lOOOkgrrr 3 , Cp = 4. lδkJkg^K "1 @ 27°C - The liquid cooled refrigerant condenser permits lengthy high pressure high cost refrigerant hoses and fittings needed for air cooled arrangements to be replace by low pressure low cost cooling liquid hoses and fittings, with a corresponding reduction in system refrigerant volume. Whilst the condenser stage 202 has been described primarily in relation to a x stacked plate' embodiment; it will be \ι appreciated that other embodiments (particularly other water cooled embodiments) could be switched to perform adequately.

Claims: Claims : 1. An integrated automotive compressor and cbndenser unit comprising: (i) a compressor sub-unit stage arranged to compress refrigerant; and, (ii) a condenser sub-unit stage arranged to perform a condensing operation on the refrigerant exiting the compressor stage; wherein the condenser and compressor sub-units are mounted together to form an integrated unit and such that the refrigerant exits the compressor sub-unit stage directly into the condenser sub-unit stage across an interface comprising or including a gasket or seal means positioned between the sub units. 2. A unit according to claim 1, wherein the outer housing for the combined unit comprises the outer housing respectively of the sub-unit compressor and the sub- unit condenser. 3. A unit according to claim 1 or claim 2, wherein the compressor includes a refrigerant outlet orifice and the condenser includes a refrigerant inlet orifice, the sub-units being mounted together such that the respective orifices co-align and are urged toward one another to define the flow path between the sub-units. A unit according to any preceding claim, wherein a seal or gasket is interposed between the compressor stage and condenser stage. 5. A unit according to any preceding claim / wherein the condenser stage sub unit and compressor stage sub unit are fabricated separately and joined subsequently in a single self-supporting unit; external housing or casing portions of the sub unit defining the external housing or casing for the combined integrated unit . 6. A unit according to claim 5 wherein the condenser stage and compressor stage are secured or held fast to one another. ' M 7. A unit according to any preceding claim, wherein the condenser stage comprises : (i) a refrigerant flowpath; and, (ii) a liquid coolant flowpath in thermal heat transfer contact with the refrigerant flowpath. 8. A unit according to claim 7, wherein the condenser stage refrigerant flowpath comprises a first gallery system, and the liquid coolant flowpath comprises a second gallery system, the first and second gallery systems being substantially sealed from one another. 9. A unit according to claim 8, wherein the condenser stage gallery systems are defined by a plurality of stacked elements. 10. A unit according to claim 9, wherein the stacked elements defining the condenser stage gallery systems comprise nested shell and/or plate elements spaced to define the respective gallery systems. 11. An automotive refrigeration/air conditioning system comprising a compressor stage/condenser stage unit according to any preceding claim.

Inventors: WHITE KEVIN, WHITE, KEVIN
Applicants: LLANELLI RADIATORS LTD, WHITE KEVIN, LLANELLI RADIATORS LIMITED, WHITE, KEVIN
Application year: 2001
Main classification: B60H1
IPC codes: B60H1, F25B39, F28D9, F28F9