Patent Publication Number: US-6338254-B1

Title: Refrigeration sub-cooler and air conditioning dehumidifier

Description:
RELATED APPLICATIONS 
     The present application claims the benefit of U.S. provisional application Ser. 60/168,336 filed Dec. 1, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention pertains to a novel method of dehumidifying an environment, which includes a refrigeration system and an air conditioning system while reducing the operational cost. 
     2. Description of the Related Art 
     Prior art systems have used refrigeration systems condensers to reheat the environment. This approach utilizes the heat which would normally be rejected to the outside environment to heat the inside environment. The Hy-Dry system sold by DTE Energy utilizes the liquid line from an air conditioning system to heat the air after it has passed over the cooling coil and air conditioning system&#39;s liquid is sub-cooled in the process. This allows the unit to discharge air at a higher temperature causing a lower net ejected humidity. Although, in this situation dehumidification may or may not take place there is no change in the coefficient of performance of the over all system other than that which is due to enlarging the heat transfer surface. That is, the same effect could be generated by simply increasing the cooling coil surface. While other prior art systems have used desiccant wheels or they have operated the reheat, which in turn causes the air conditioning to turn on and remove the moisture. In the later cases the net result is at an added operational cost. 
     OBJECTIVES AND ADVANTAGES OF THE INVENTION 
     Table of Functions, Purposes, Objectives, Goals, Tasks 
     
       
         
           
               
               
             
               
                   
               
               
                 OBJECTIVE 
                 SOLUTION 
               
               
                   
               
             
            
               
                 REFRIGERATION LIQUID IS 
                 PASS AIR FROM THE CONDI- 
               
               
                 SUB-COOLED 
                 TIONED ENVIRONMENT OVER 
               
               
                   
                 THE SUB-COOLING COIL OR PASS 
               
               
                   
                 A SECONDARY FLUID OVER THE 
               
               
                   
                 LIQUID AND THEN THROUGH THE 
               
               
                   
                 CONDITIONED ENVIRONMENTS 
               
               
                   
                 AND FURTHER SUB-COOL THE 
               
               
                   
                 LIQUID WITH A HEAT EX- 
               
               
                   
                 CHANGER ON THE AIR 
               
               
                   
                 CONDITIONER 
               
               
                 LOWER ENERGY COST OF 
                 SUB-COOL THE LIQUID WITH A 
               
               
                 THE REFRIGERATION 
                 COMPRESSOR OPERATING AT AIR 
               
               
                 SYSTEM IS ACHIEVED BY 
                 CONDITIONING EFFICIENCY THE 
               
               
                 REMOVING PART OF THE 
                 LATENT LOAD ON THE REFRIG- 
               
               
                 ENERGY AT LESS COST 
                 ERATION SYSTEM IS REDUCED 
               
               
                   
                 DUE TO THE LOWER HUMIDITY IN 
               
               
                   
                 THE REFRIGERATED 
               
               
                   
                 ENVIORNMENT 
               
               
                 DEHUMIDIFICATION IS 
                 BY HEATING CONDITIONED 
               
               
                 ACHIEVED 
                 ENVIRONMENT AIR WITH THE 
               
               
                   
                 WARM LIQUID AND CAUSING THE 
               
               
                   
                 AIR CONDITIONING COMPRESSOR 
               
               
                   
                 TO OPERATE 
               
               
                 LOWER HUMIDITY IN THE 
                 PASS AIR OVER THE A/C COIL 
               
               
                 DISCHARGE AIR DUCT 
                 FIRST AND THEN PASS THE AIR 
               
               
                 WHICH RESULTS IN LESS 
                 OVER THE SUB-COOLING HEAT 
               
               
                 FAVORABLE ENVIRON- 
                 FOR EXCHANGER 
               
               
                 MENT FUNGUS GROWTH 
               
               
                   
               
            
           
         
       
     
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a schematic of a dehumidification sub-cooling system utilizing the current invention. 
     FIG. 2 is a schematic of a dehumidification sub-cooling system utilizing the current invention in which the refrigeration system has parallel piped evaporators. 
     FIG. 3 is a schematic of a dehumidification sub-cooling system utilizing the current invention utilizing an additional heat exchanger on the air conditioning system to further sub-cool the refrigeration liquid. 
     FIG. 4 is a schematic of a dehumidification sub-cooling system utilizing the current invention in which energy in refrigeration liquid is transferred to a secondary fluid prior to being discharged into the air conditioned space. 
     FIG. 5 is a schematic of a dehumidification sub-cooling system utilizing the current invention which includes piping for using conventional reheat. 
     FIG. 6 is a schematic of a conventional refrigeration system used for dehumidification. 
    
    
     SUMMARY OF THE INVENTION 
     The current invention is an efficient method for dehumidifying an environment and refrigerating a second environment with a closed loop refrigeration system consisting of compressing refrigerant with a refrigeration compressor to a high temperature and pressure, condensing the high pressure refrigerant to a liquid at a high temperature, circulating high pressure liquid refrigerant through a heat exchanger which is used to transfer energy from the liquid to an environment which is being air conditioned at a higher efficiency and which may contain the refrigerated environment. The liquid is then evaporated to a gas at a low pressure in a refrigeration evaporator coil. 
     Elements and Functions 
     Table of Element and Numbers and Figures 
     
       
         
           
               
               
               
               
             
               
                   
               
               
                 # 
                   
                 ELEMENT DESCRIPTION 
                 FIGURES 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 10 
                   
                 REFRIGERATION COMPRESSOR 
                 1,2,3,4,5,6 
               
               
                 10 
                 B 
                 AIR CONDITIONING SYSTEM 
                 1 
               
               
                   
                   
                 COMPRESSOR 
               
               
                 15 
                   
                 COMPRESSOR SUCTION 
                 1,2,3,4,5,6 
               
               
                 15 
                 B 
                 AIR CONDITIONING COMPRESSOR 
                 1,2 
               
               
                   
                   
                 SUCTION 
               
               
                 20 
                   
                 COMPRESSOR DISCHARGE 
                 1,2,3,4,5,6 
               
               
                 20 
                 B 
                 AIR CONDITIONING COMPRESSOR 
                 1 
               
               
                   
                   
                 DISCHARGE 
               
               
                 30 
                   
                 CONDENSER 
                 1,2,3,4,5,6 
               
               
                 30 
                 B 
                 AIR CONDITIONING SYSTEM CONDENSER 
                 1 
               
               
                 40 
                   
                 THREE WAY VALVE 
                 5,6 
               
               
                 60 
                   
                 REHEAT COIL 
                 1,2,3,4,5,6 
               
               
                 70 
                   
                 RECEIVER 
                 1,2,3,4,5,6 
               
               
                 70 
                 B 
                 AIR CONDITIONING SYSTEM RECEIVER 
                 1 
               
               
                 75 
                   
                 LIQUID REFRIGERANT 
                 1,2,3,4,5,6 
               
               
                 75 
                 B 
                 AIR CONDITIONING SYSTEM LIQUID 
                 1 
               
               
                   
                   
                 REFRIGERANT 
               
               
                 80 
                   
                 CHECK VALVE 
                 5 
               
               
                 81 
                   
                 CHECK VALVE 
                 5 
               
               
                 105 
                   
                 REFRIGERATION CONDENSER FAN 
                 1,2,3,4,5,6 
               
               
                 105 
                 B 
                 CONDENSER FAN AIR CONDITIONING 
                 1 
               
               
                   
                   
                 SYSTEM 
               
               
                 150 
                   
                 THREE WAY VALVE 
                 5,6 
               
               
                 180 
                   
                 LIQUID EVACUATION SOLENOID 
                 5,6 
               
               
                 200 
                   
                 REFRIGERATED AREA 
                 1,2,3,4,5,6 
               
               
                 200 
                 B 
                 AIR CONDITIONED SYSTEM AIR HANDLER 
                 1,2,3,4,5,6 
               
               
                 200 
                 C 
                 REFRIGERATED AREA C 
                 1,2,3,4,5,6 
               
               
                 220 
                   
                 EVAPORATOR 
                 1,2,3,4,5,6 
               
               
                 220 
                 B 
                 AIR CONDITIONING EVAPORATOR 
                 1,2 
               
               
                 220 
                 C 
                 PARALLEL PIPED EVAPORATOR C 
                 2,3,4,5,6 
               
               
                 225 
                   
                 EXPANSION VALVE 
                 1,2,3,4,5,6 
               
               
                 225 
                 B 
                 AIR CONDITIONING SYSTEM EXPANSION 
                 1 
               
               
                   
                   
                 VALVE 
               
               
                 225 
                 C 
                 REFRIGERATION SECOND EVAPORATOR 
                 2,3,4,5,6 
               
               
                   
                   
                 EXPANSION VALVE 
               
               
                 226 
                   
                 EVAPORATOR FAN FOR EVAPORATOR 220 
                 1,2,3,4,5,6 
               
               
                 226 
                 B 
                 AIR CONDITIONING EVAPORATOR FAN 
                 1,2,3,4,5,6 
               
               
                   
                   
                 FOR EVAPORATOR 220B 
               
               
                 226 
                 C 
                 AIR CONDITIONING EVAPORATOR FAN 
                 1,2,3,4,5,6 
               
               
                   
                   
                 FOR EVAPORATOR 220C 
               
               
                 302 
                   
                 303 AIR CONDITIONING SUCTION OUTLET 
                 3 
               
               
                 303 
                   
                 AIR CONDITIONING SUCTION - 
                 3 
               
               
                   
                   
                 REFRIGERATION LIQUID HEAT LIQUID 
               
               
                   
                   
                 HEAT EXCHANGER 
               
               
                 304 
                   
                 303 AIR CONDITIONING SUCTION INLET 
                 3 
               
               
                 306 
                   
                 AIR CONDITIONING LIQUID LINE 
                 1,2,3,4,5,6 
               
               
                 310 
                   
                 AIR FLOW 
                 1,2,3,4,5,6 
               
               
                 500 
                   
                 SECONDARY FLUID CIRCULATING PUMP 
                 4 
               
               
                 502 
                   
                 SECONDARY FLUID HEAT EXCHANGER 
                 4 
               
               
                   
                   
                 REFRIGERANT FLUID PATH 
               
               
                 503 
                   
                 SECONDARY FLUID HEAT EXCHANGER 
                 4 
               
               
                   
               
            
           
         
       
     
     Further objectives and advantages of the invention will become apparent from a consideration of the drawings and ensuing description. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Description of FIG.  1 : 
     In FIG. 1 a refrigeration system ejects energy from its liquid into a coil 60 located in air conditioning system air handler  200   b.  A refrigeration compressor  10  compresses a refrigerant to a high pressure and temperature discharges it through pipe  20  to condenser  30 . Air is blown across condenser  30  causing the gas to condense into a liquid. Liquid  75  is accumulated in receiver tank  70 . Liquid is then routed to liquid cooling coil  60  where it gives up energy and as a consequence the liquid temperature going into coil  60  is higher than the liquid temperature leaving. The refrigerant is then routed to an evaporator  200  where it is expanded through an expansion valve  225 . The expanded refrigerant is warmed by air blown across evaporator  220  by fan  226 . The expanded gas is routed back to compressor suction  15  where compressor  10  starts the cycle over. 
     The air conditioning system performs the same function of removing energy from an evaporator area  220   b  and discharging it through a condenser  30   b  at a lower compression ratio. It however does this with a higher efficiency since the level to which it must raise the compression is less than that of the refrigeration system. It also means that the cost of running the refrigeration system is less, for many reasons as will be described herein. The adding of heat to the air conditioning system has the added benefit of causing additional air conditioning operation resulting in dehumidification of the air conditioned environment. Which has cascaded benefits of producing a lower humidity in the environment of air conditioned space and the refrigeration space. This produces less latent heat load on the refrigeration systems. 
     Description of FIG.  2 : 
     In FIG. 2 an additional refrigeration area  200   c  is shown which exists in parallel with refrigeration area  200 . The refrigeration piping of this evaporative cooling coil system is paralleled with that of  200 . The operation of the remainder of the system is identical to area  200  in FIG.  1 . 
     Description of FIG.  3 : 
     In FIG.  3  and additional heat exchanger  303  has been added to further cool the refrigeration liquid with the efficiency of the air conditioning system. The refrigerant expanded by expansion valve  225   b  is passed through the heat exchanger  303 . The liquid from the refrigeration system is passed through the heat exchanger and is lowered closer to the air conditioner suction temperature. The additional energy removed from the refrigeration system liquid is now removed by the air conditioning system which is more efficient than the refrigeration system. 
     Description of FIG.  4 : 
     In FIG. 4 a secondary fluid heat exchanger  503  is utilized to transfer energy from the refrigeration liquid to the air conditioning environment. Refrigeration liquid  75  is circulated through the secondary fluid heat exchanger  503  where energy is transferred to the secondary fluid. Secondary fluid pump circulates the fluid to air reheat exchanger  60  where the energy is transferred to the air conditioned space  200   b  for removal by the air conditioning system. It should be noted that exchanger  60  in all the figures only needs to be located in the air conditioned space to be effective. One convenient and advantageous location would be underneath one of the open (lacking doors) refrigeration fixture. 
     Description of FIG.  5 : 
     In FIG. 5 a refrigeration circuit is shown which allows for conventional hot gas reheat of the air conditioned space  200   b  in addition to the liquid cooler dehumidification system disclosed herein. When liquid cooling is required the liquid is circulated through reheat coil  60  by switching 3 way valves  40  and  150  into the appropriate positions. When full heat is required the discharge gas is circulated through reheat coil  60  positioning valves  40  and  150  into the appropriate positions. 
     Someone skilled in the art would be aware after reading the information contained herein that multiple refrigeration systems could have the energy from the liquid lines injected into the air conditioning system. Any refrigeration system with an efficiency which is less than the air conditioning system would produce a net efficiency gain. 
     While the previous description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. The scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents. 
     Description of FIG.  6 : 
     A prior art system is show in FIG. 6 which allows for conventional hot gas reheat of the air conditioned space  200   b.