Abstract:
In at least one aspect of this disclosure, a refrigeration system includes an evaporatively cooled condenser configured to transfer heat from the refrigeration system to an atmosphere, an air inlet in fluid communication with the condenser, and an evaporative cooling medium disposed between the atmosphere and the condenser such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow before passing the airflow over the condenser. The evaporative cooling element can improve system cooling efficiency by 20-50% depending on temperature conditions or even greater in dry climates.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to and the benefit of U.S. Provisional Application Ser. No. 61/775,056, filed Mar. 8, 2013, the entire contents of which are incorporated by reference herein. 
     
    
     STATEMENT OF GOVERNMENT RIGHTS 
       [0002]    This subject matter of this disclosure was made with government support under DE-EE0003920 awarded by the Department of Energy. The government has certain rights to at least a portion of the subject matter of this disclosure. 
     
    
     BACKGROUND 
       [0003]    1. Field 
         [0004]    The present disclosure relates to refrigeration systems, more particularly to commercial air conditioner systems. 
         [0005]    2. Description of Related Art 
         [0006]    Residential air conditioning units can absorb a large amount of energy to cool a certain space. Air conditioning in summer is the largest factor accounting for utility peak electrical generation demand. Higher efficiency cooling systems are highly desirable for a means to reduce energy usage and save electrical cost. 
         [0007]    Conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for more efficient refrigeration systems, particularly under the hottest conditions. There also remains a need in the art for such a system that is easy to make and use. The present disclosure provides a solution for this problem. 
       SUMMARY 
       [0008]    In at least one aspect of this disclosure, a refrigeration system includes a condenser configured to transfer heat from the refrigeration system to the surrounding atmosphere, an air inlet in fluid communication with the condenser, and an evaporative cooling medium disposed between the condenser and the air inlet such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow passing into the condenser. 
         [0009]    The evaporative cooling medium can include a corrugated cellulose pad. In some embodiments, the evaporative cooling medium can be attached to a frame surrounding the condenser and/or can be about 2 to about 6 inches thick. 
         [0010]    The refrigeration system can further include a wetting system configured to wet the evaporative cooling medium. In some embodiments, the wetting system can include a water reservoir configured to collect water from a water source, at least one tube including a water reservoir opening in fluid communication with the water reservoir and an evaporative cooling medium opening configured to provide the water to the evaporative cooling medium, and at least one pump configured to pump water from the water reservoir to the evaporative cooling medium. 
         [0011]    The wetting system can further include a water distribution device disposed between the evaporative cooling medium and the evaporative cooling medium opening of the tube, the water distribution device configured to evenly distribute water to the evaporative cooling medium. The water distribution device can include a plurality of holes in the tube. 
         [0012]    In at least one aspect of this disclosure, an air conditioning unit can include a condenser configured to transfer heat from the air conditioning unit to the surrounding atmosphere, at least one air inlet in fluid communication with the condenser, an evaporative cooling medium disposed between the atmosphere and the air inlet such that at least a portion of an airflow from the atmosphere passes through the evaporative cooling medium to reduce the temperature of the airflow before passing the airflow over the condenser, and a wetting system configured to wet the evaporative cooling medium. 
         [0013]    In at least one aspect of this disclosure, an air conditioner efficiency kit includes an evaporative cooling medium configured to attach to an air conditioning unit and cover at least a portion of an air intake of the air conditioning unit, and a wetting system configured to wet the evaporative cooling medium, the wetting system configured to attach to attached to the air conditioning unit to provide water to the evaporative cooling medium. 
         [0014]    These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, embodiments thereof will be described in detail herein below with reference to certain figures, wherein: 
           [0016]      FIG. 1A  is a front exploded, perspective view of an embodiment of a portion of a refrigeration system in accordance with this disclosure; 
           [0017]      FIG. 1B  is a rear exploded, perspective view of the portion of the refrigeration system of  FIG. 1A ; 
           [0018]      FIG. 1C  is a partial, exploded perspective view of a portion of a refrigeration system in accordance with this disclosure; 
           [0019]      FIG. 1D  is a plan view of a refrigeration system in accordance with this disclosure, shown partially disposed within an enclosed space; 
           [0020]      FIG. 2  is a perspective view of an embodiment of a portion of a refrigeration system in accordance with this disclosure; and 
           [0021]      FIG. 3  is a partial view of the evaporative medium of, showing an embodiment of a water distribution system in accordance with this disclosure disposed thereon. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, embodiments of a refrigeration system  100 , and portions thereof, in accordance with this disclosure is shown in  FIGS. 1A-3 . The systems and methods described herein can be used to increase efficiency of air conditioning or any other suitable purpose. 
         [0023]    In at least one aspect of this disclosure, referring to  FIGS. 1A-1D , a refrigeration system  100  (e.g., a heat pump) can include a housing  101  defining one or more air inlets  103   a,    103   b  and at least one air outlet  105 . 
         [0024]    The refrigeration system  100  also includes at least one condenser  117  configured to transfer heat from the refrigeration system  100  (e.g., from a refrigerant flowing within the condenser) to an atmosphere (e.g., outdoor air). The condenser  117  can be any suitable condenser assembly configured to operate in a refrigeration cycle. The air inlets  103   a,    103   b  can be in fluid communication with the condenser  117  such that air can be drawn through housing  101  and through condenser  117  in any suitable manner. 
         [0025]    The refrigeration system  100  can include one or more evaporative cooling media  107   a ,  107   b  disposed between the atmosphere and the air inlets  103   a,    103   b  such that at least a portion of airflow from the atmosphere passes through the evaporative cooling media  107   a,    107   b  to reduce the temperature of the airflow before passing the airflow over the condenser  117 . In some embodiments, at least one evaporative cooling medium (e.g., evaporative cooling medium  107   a  and or  107   b ) can be disposed between the housing  101  and the condenser  117  in any suitable manner such that the housing  101  contains at least a portion of the evaporative cooling medium (e.g., evaporative cooling medium  107   a  and/or  107   b ). 
         [0026]    The evaporative cooling media  107   a,    107   b  can include any suitable medium configured to evaporate a liquid (e.g. water) to a gas (e.g. air) flowing therethrough. In some embodiments, the evaporative cooling media  107   a,    107   b  can be one or more corrugated cellulose pads. The evaporative cooling media  107   a,    107   b  can be of any suitable dimension or thickness, including, but not limited to, about 2 inches to about 6 inches thick. In embodiments where there are multiple air inlets  103   a,    103   b  as shown in the drawings, the different evaporative cooling media  107   a,    107   b  may have the same or different thickness and/or material composition. 
         [0027]    Referring additionally to  FIG. 2 , in some embodiments, the evaporative cooling media  107   a,    107   b  can be attached to at least one frame (e.g., frames  109   a,    109   b ) surrounding the condenser  117  or a portion thereof. The frame (e.g., frames  109   a,    109   b ) can be of any suitable size or shape to hold evaporative cooling media  107   a,    107   b  to the housing  101  of refrigeration system  100 . The frame (e.g., frames  109   a,    109   b ) can be of any suitable material, including, but not limited to, plastic, metal, etc. 
         [0028]    Additionally referring to  FIGS. 3 , the refrigeration system  100  can further include a wetting system disposed on the refrigeration system  100  and/or over or otherwise in fluid communication with the evaporative medium (e.g., evaporative cooling medium  107   a  and/or  107   b ) such that the wetting system is configured to wet the evaporative cooling medium. The wetting system can include any suitable system for wetting the evaporative cooling medium (e.g., a hose or water supply configured to selectively provide water to the evaporative cooling medium). 
         [0029]    In some embodiments, the wetting system can include a water reservoir  111  configured to collect water from any suitable water source (e.g., rain water, a pressurized water supply, and/or condensate from cooling coils). The wetting system can include at least one tube  115  including a water reservoir opening in fluid communication with the water reservoir  111 . The tube  115  can also include at least one evaporative cooling medium opening (see end of tube  115  shown in  FIG. 4 ) configured to provide the water to the evaporative cooling medium (e.g., media  107   a,    107   b ). While tube  115  is shown having a single open end in  FIG. 4 , the tube  115  can be configured to extend any suitable length and include any suitable number of holes therein to provide water to the evaporative cooling medium and/or a water distribution system as described herein. 
         [0030]    In some embodiments, the water reservoir  111  is in direct fluid communication with at least a portion of the evaporative cooling medium (e.g., evaporative cooling medium  107   a  and/or  107   b ) such that the evaporative cooling medium can soak up water in the water reservoir  111 . In one embodiment, the refrigerant line from the condenser outlet can be piped through the water reservoir to provide additional sub-cooling in the refrigeration process and greater efficiency. 
         [0031]    The wetting system can alternatively or additionally include at least one pump  113  configured to pump water from the water reservoir  111  to the evaporative cooling medium (e.g., media  107   a,    107   b ). The pump  113  can be any suitable type of fluid pump and may be configured to operate using a low power source. The pump  113  can also be connected to and/or include a microcontroller for controlling activation of the pump  113  according to any suitable algorithm implemented via any suitable software and/or hardware. The low wattage DC pump may be powered by a rectified AC current or otherwise directly from solar photovoltaic panels. 
         [0032]    In some embodiments, the wetting system can further include a water distribution device that distributes water to the evaporative cooling medium (e.g., media  107   a,    107   b ) through one or more openings in tube  115  as shown in  FIG. 3 . The water distribution device is configured to evenly distribute water to the evaporative cooling medium (e.g., media  107   a,    107   b ). The water distribution device can be included and/or disposed within frame (e.g., frames  109   a,    109   b ) such that it sits above the evaporative cooling medium (e.g., media  107   a,    107   b ), however, any other suitable configuration is contemplated. 
         [0033]    In at least one aspect of this disclosure, a refrigeration system  100  can be contained in a single housing  101  and used as an air conditioning system (e.g., a large central air conditioner unit). A compressor (not shown) is included within housing  101  for compressing the refrigerant upstream of the condenser  117 . Also, at least one expansion valve can be included along a refrigerant line  119  downstream of the condenser  117 . 
         [0034]    The refrigeration system  100  releases heat into the atmosphere through condenser  117 . The colder the outside air, the more efficiently heat is transferred to the atmosphere. In this respect, in the embodiments shown in the drawings, the refrigeration system  100  draws air through the evaporative media  107   a,    107   b  and cools the air through evaporation of water into the air. When the air passes through the inlets  103   a,    103   b  to the condenser  117 , it is of a lower temperature than the atmosphere air allowing for improved heat transfer and higher overall efficiency of the refrigeration system  100 . In detailed experiments by the inventors, the use of the evaporative cooling system and better system fan, AC efficiency was increased by 30% over the best currently-available technologies with improvements to peak energy-efficiency ratio (EER) of 41%. 
         [0035]    In at least one aspect of this disclosure, an air conditioner efficiency kit, e.g., a retrofit kit configured to retro fit onto an air conditioning unit or portion thereof, includes an evaporative cooling medium (e.g., media  107   a,    107   b ) configured to attach to an air conditioning unit and cover at least a portion of an air intake (e.g., intakes  103   a,    103   b ) of the air conditioning unit, and a wetting system configured to wet the evaporative cooling medium, the wetting system configured to attach to the air conditioning unit to provide water to the evaporative cooling medium (e.g., media  107   a,    107   b ). The kit can further include a water distribution system as part of the wetting system as described above. 
         [0036]    In at least one aspect of this disclosure, a method includes evaporating water into air at an inlet of a refrigeration system condenser such that the air cools before reaching the condenser. The method can further include automatically wetting an evaporative medium using a wetting system as described herein. 
         [0037]    The methods and systems of the present disclosure, as described above and shown in the drawings, provide for a refrigeration system  100  with superior properties including improved efficiency. While the apparatus and methods of the subject disclosure have been shown and described with reference to embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the spirit and scope of the subject disclosure.