Abstract:
A refrigerant flow processor has a vessel with an inlet for receiving recirculating refrigerant from a motor driven compressor and a condenser and having an outlet for returning the refrigerant to an evaporator through an expansion valve. The vessel is configured to establish a vortexing motion of liquefied refrigerant as it travels from the inlet to the outlet. A helical flow guiding component at the vessel outlet causes a highly turbulent flow within the conduit which connects the outlet to the expansion valve. The flow processor reduces energy consumption and operating cost by reducing the load on the motor driven compressor.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to heat exchanging systems in which a recirculating fluid refrigerant absorbs heat at an evaporator and releases heat at a condenser. More particularly the invention relates to apparatus for processing the refrigerant flow between the condenser and the evaporator in order to enhance the efficiency of the system. 
     Heat exchanging systems to which the invention is applicable include refrigerating systems, air conditioning systems and heat pumping systems among other examples. Systems of this kind have a motor driven compressor which pressurizes gaseous fluid that is received from an evaporator coil. The pressurizing raises the temperature of the fluid which is then transmitted to a condenser coil. The fluid releases heat into the region which is adjacent to thee condenser coil and condenses to liquid form as it cools. The condensed and cooled fluid is then returned to the evaporator coil where it expands and absorbs more heat from the region adjacent to the evaporator coil. Thus heat removed from the region adjacent to the evaporator coil is transferred to the region adjacent to the condenser coil. 
     Operation of the motor which drives the compressor consumes costly energy. Energy can be saved and operating costs can be reduced by increasing the thermodynamic efficiency of the system. It has heretofore been recognized that the energy which is required to transfer a given amount of heat at a given rate is affected by the compression ratio at the compressor and by the temperature of the condensed fluid as it enters the evaporator coil. Any steps which enable the compressor to deliver the fluid to the condenser coil at a lower head pressure increases efficiency. A lower fluid temperature at the inlet of the evaporator coil enables absorption of a greater amount of heat in the evaporator coil and thereby further increases efficiency. 
     It has also been recognized that the required compression ratio and also the temperature at the inlet of the evaporator coil can both be lowered by flow processing means in the flow path from the condenser coil to the evaporator coil. Prior U.S. Pat. No. 5,426,956 discloses flow processing means for this purpose, the specification and drawings of that patent being herein incorporated by reference. The flow processing means of that prior patent include a vessel which receives the condensed fluid from the condenser coil and delivers the fluid to the expansion valve and evaporator coil. The vessel holds a volume of condensed fluid that may otherwise be backed up into the condenser coil and thereby provides for increased condensation within the condenser coil. Further condensation takes place in the vessel itself. The increased condensation raises efficiency by lowering the discharge pressure at the outlet of the compressor. Heat transfer through the wall of the vessel results in further cooling of the condensed fluid and the heat transfer is enhanced by configuring the vessel to swirl the flow in a vortex as it travels toward the outlet of the vessel. Further cooling occurs by heat transfer through the wall of the conduit which delivers the condensed fluid from the vessel to the expansion valve and evaporator coil. In the apparatus of the above identified prior patent, a turbulator element at the outlet of the vessel enhances this further cooling by enhancing the rotational motion of the flow as it enters the conduit. Flow turbulence this kind increases heat loss through the conduit wall as the flow travels along the conduit thereby causing further cooling of the flow. 
     The presence of the turbulence inducing element in the flow path causes some back pressure which must be counteracted by the compressor. An object of this invention is to provide further energy saving and operating cost reduction by increasing turbulence in the flow which is discharged from the vessel and by reducing the back pressure which is created by the turbulence increasing component. 
     The present invention is directed to overcoming one or more of the problems discussed above. 
     BRIEF SUMMARY OF THE INVENTION 
     In one aspect the present invention provides a flow processing vessel having an inlet for receiving a flow of liquefied refrigerant from a refrigerant condenser having an outlet for delivering a flow of the liquefied refrigerant to an expansion device and evaporator through an outlet conduit. The vessel is configured to provide vortex rotation of the liquid as it travels downward from the inlet towards the outlet and has a turbulence enhancing component at the outlet for causing turbulence of the flow within the outlet conduit. The turbulence enhancing component has a flow guiding member with a helical inner surface that extends vertically within the flow at the outlet and which is oriented to impart rotational motion to the flow as it passes downward through the outlet. 
     In another aspect of the invention, a refrigerant flow processor includes a vessel forming an upright cylindrical vortex chamber and having a fluid inlet at an upper region thereof and a fluid outlet at the center of a bottom portion thereof. A flow delivery tube extends from the fluid inlet within the chamber, the tube being angled to direct incoming refrigerant towards a side region of the vortex chamber to reinforce rotation of fluid flow therein. An upright coupling sleeve extends downward from the fluid outlet and is adapted to receive a fluid outflow conduit. A vortex generator extends downward through the outlet and into an upper region of the coupling sleeve. The vortex generator has a flow guiding member with a helical inner surface which is curved to conform with the path of the liquid flow which is undergoing vortex rotation and descending through the outlet. 
     The invention reduces the discharge pressure at the compressor and lowers the temperature of the refrigerant which enters the expansion valve and evaporator. Power consumption by the motor driven compressor is thereby reduced to realize a substantial reduction in the operating cost of the system. 
    
    
     The invention, together with further objects and advantages thereof, may be further understood by reference to the following detailed description of a preferred embodiment of the invention and by reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevation section view of a refrigerant flow processor vessel with associated components of a typical heat exchanging system being shown in schematic form. 
     FIG. 2 is a cross section view of the flow processor vessel taken along line  2 — 2  of FIG.  1 . 
     FIG. 3 is a perspective view of a turbulence enhancing component, termed a vortex generator, which is disposed at the outlet of the vessel of the preceding figures. 
     FIG. 4 is an elevation section view of the fluid inlet region of the vessel of FIGS. 1 and 2 showing a modification which may be made to accommodate to fluid input conduits of different sizes. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring jointly to FIGS. 1 and 2 of the drawings, a refrigerant flow processor  11  embodying the invention includes a vessel  12  with an internal chamber  13  through which a recirculating refrigerant  14  passes. When installed in a typical heat exchanging system  16 , the vessel  12  receives liquefied refrigerant  14  from a condenser coil  17  and delivers the refrigerant flow to an evaporator coil  18  through an expansion valve  19 . Gasified refrigerant  14  from evaporator coil  18  is recirculated to condenser coil  17  through a compressor  21 . 
     In this description land in the appended claims, the term “fluid” should be understood to refer to refrigerant  14  in either of its liquid or gaseous phases. The term “refrigerant” is used in keeping with common practice in the art although the heat pumping system  16  itself may variously be called a refrigerating system, an air conditioning system, a heat pump or be identified by various other terms depending on the function which it is adapted to serve. 
     In this example, vessel  12  is formed by an upright cylindrical shell  22  closed by upper and lower end caps  23  and  24  respectively which are of dished configuration. An upper coupling sleeve  26  extends outward from a fluid inlet opening  27  situated at an upper region of the chamber  13 . The inflow conduit  28  which connects the vessel to condenser coil  17  extends into upper coupling sleeve  26  and is preferably microwire welded in place. The conduit  28  connection can be soldered or be established by other means but microwire welding provides greater assurance against leaks. 
     A lower coupling sleeve  29  extends downward from an outlet opening  31  in the lower end cap  24 . Outlet opening  31  and lower sleeve  29  are centered on the vertical central axis  32  of the cylindrical shell  22 . The outflow conduit  33  which delivers refrigerant  14  from vessel  12  to expansion valve  19  is fitted into a lower portion of the lower coupling sleeve  29  and is preferably microwire welded in place. 
     The above described configuration of the flow processor  11  creates a vortex in the downward flow of refrigerant  14  towards outlet  31 . Coreolis force causes the liquid to rotate, as indicated by arrow  34  in FIG. 2, as it travels downward and inward towards the outlet  31 . Referring again to FIGS. 1 and 2, the vortexing effect is enhanced by a fluid delivery tube  35  in chamber  13  which extends from upper coupling sleeve  26 . Tube  35  is angle downwardly and sidewardly to direct the incoming stream of liquid  14  to a side region of the chamber  13  at which it reinforces the rotational motion of the liquid. The presence of the vessel  12  and the vortexing flow therein in the refrigerant flow path provides the efficiency increasing effects which have been previously described. 
     A vortex generator component  36  further enhances the rotational motion of the liquid as it enters the conduit  33  which delivers the flow to expansion valve  19 . This causes the flow along outflow conduit  33  to be a highly turbulent flow with beneficial effects which will hereinafter be discussed. 
     Referring to FIG. 3 in conjunction with FIG. 1, the vortex generator  36  has an annular base flange  37  which is seated against a conforming annular shelf  38  situated at a middle region of the lower coupling sleeve  29  above outflow conduit  33 . A flow guiding member  38  of helical configuration extends upward from base flange  37  into the lowermost region of chamber  13 . The pitch of the helix defined by flow guiding member  38  is sufficiently large to establish a helical slot  39  in the side wall of the vortex generator  36  that enables entry of fluid along the length of the flow guiding member. The helical flow guiding member  38  curves in the same angular direction that is traveled by the rotating liquid in chamber  13 . Thus the helical inside surface  41  of member  38  intercepts incoming liquid and guides it downward while preserving and enhancing the rotation of the flow as it descends into outflow conduit  33 . 
     Under optimum conditions, the angular component of the flow in conduit  33  may persist for a distance of around fifty feet. This distance is reduced by sharp turns or elbows in the conduit. Thus can be advantageous to provide a sizable radius of curvature at turns in instances where the conduit  33  extends along a non-linear path. 
     The inside diameter of the vortex generator  36  and the inside diameter of the shelf  38  against which it is seated are preferably at least as large as the inside diameter of outflow conduit  33 . Thus the vortex generator  36  does not constrict the flow path of fluid entering the outflow conduit  33 . 
     Referring to FIG. 1 in particular, the volume of liquid refrigerant  14  in vessel  12  normally extends to a level which is above the bottom of the vessel and below the outlet of fluid delivery tube  35  although the level may fluctuate temporarily in response to 6 changes in operating conditions. The vessel wall may be provided with a sight gauge  42  located at the normal level of the liquid refrigerant  14  to enable monitoring of the level. The sight gauge may be of the known form having a transparent window  43 . The vessel  11  may also be provided with a fusible plug vent  44 , preferably located in the upper end cap  23 , of the type containing a small fusible plug (not shown) that melts to vent gaseous refrigerant if the temperature in the vessel should exceed a maximum operating value. 
     In this example of the invention, the fluid inflow conduit  28  from condenser coil  17  has an outside diameter corresponding to the inside diameter of the upper coupling sleeve  26 . Referring to FIG. 4 in conjunction with FIG. 1, an adapter bushing  46  may be inserted into coupling sleeve  26  to enable installation of the same flow processor  11  in a system having an inflow line  28   a  of smaller diameter. Bushing  46  has an outside diameter conforming to the inside diameter of the upper coupling sleeve  26  and having a stepped axial passage. One end  47  of the axial passage has a diameter conforming to that of the relatively small inflow line  28   a . The other end  48  of the axial passage has a larger diameter. Thus the bushing may be reversed end to end to receive an inflow line having a diameter intermediate between the inflow line  28   a  shown in FIG.  4  and the inflow line  28  shown in FIG.  1 . 
     Referring jointly to FIGS. 1 and 2, installation of the flow processor  11  is facilitated if it can be turned in any desired angular orientation in order to accommodate to fluid inlet conduits  28  that may extend in different directions. This can be provided for by use of a mounting fixture  49  which includes an omega clamp  51 . The clamp  51  has somewhat flexible band  52  that substantially encircles vessel  12  and which has proximal ends  53  that are angled to extend outward from the vessel and then sidewardly. Ends  53  have slots  54  which enable fastening of clamp  51  to slotted arms  56  of a T-shaped mounting bracket  57  by bolts  58 . Holes  59  in the bracket  57  enable it to be fastened to a wall or other structure at the installation site. Vessel  12  may bee turned within band  52  and be raised or lowered to align input coupling  26  with a fluid inlet conduit  28 . Thereafter, ends  53  of band  52  are cinched together to clamp the vessel in place and bolts  58  are tightened. 
     As has been pointed out, vortex generator  36  substantially increases rotation of the liquid refrigerant flow as it travels along outflow conduit  33 . The rotating flow, as contrasted with a straight forward laminar flow, is a form turbulent flow which reduces flow, resistance within the conduit and which increases further cooling of the flow by heat transfer through the wall of the conduit. Decreased flow resistance reduces the output pressure which compressor  21  must provide in order to circulate the refrigerant  14  and thereby provides energy savings. Increased cooling of the flow within conduit  33  lowers the temperature of fluid entering evaporator  18  and thereby effects further energy savings by increasing the efficiency of the evaporator. 
     While the invention has been described with reference to a specific embodiment for purposes of example, many modifications and variations are possible and it is not intended to limit the invention except as defined by the following claims.