Abstract:
The present invention provides a livewell for a marine vessel for holding captive gamefish wherein the water temperature maintained in the livewell is maintained at a reduced temperature. The reduced water temperatures induces a state of reduced metabolism in the captive gamefish which prolongs the life of the gamefish in captivity. The water in the livewell is cooled by circulating water through a thermodynamic heat exchanger that transfers the heat to a refrigerant that is circulated through a conventional refrigeration cycle commonly found in air conditioning systems, freezers, and refrigerators. The refrigerant is compressed and circulated by a compressor powered by electricity from the marine vessel&#39;s batteries or electrical power system. A pair of pumps enable the water in the livewell to be circulated through the chiller assembly and to fill or empty the livewell as required.

Description:
[0001]     This application claims priority to provisional application Ser. No. 60/553,813 filed on Mar. 17, 2004 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to an apparatus for the temporary captive storage of live gamefish and other similar aquatic animals. More particularly, the present invention relates to an improved livewell apparatus for use in recreational or commercial fishing vessels utilizing a conventional refrigeration cycle to cool the water in the livewell.  
         [0004]     2. Background Information  
         [0005]     In marine vessels, it is typical to have a livewell for holding captive gamefish to hold the gamefish for relatively extended periods of time, such as up to twelve to sixteen hours covering an extended day&#39;s fishing trip. It is theorized that one of the principal causes of problems in maintaining captured fish alive is the excited nature of the fish when placed in a generally enclosed livewell or similar tank. As mentioned above, in this excited condition, fish tend to lose some portion of their scales and their natural slime secretions as well as to discharge bodily wastes and even to vomit the contents of their digestive tracts. All of this foreign matter in the water in a livewell poses a danger to the fish in that the foreign matter may become lodged in the fish&#39;s gills during normal breathing. Moreover, the excited nature of the fish significantly increases its metabolism causing it to utilize oxygen from the water at a significantly increased rate. Finally, it is known that fish are relatively sensitive to the temperature of the ambient body of water and, therefore, any difference in the temperature of the water in the livewell from that of the surrounding ambient body of water, particularly when the livewell water is elevated, may exacerbate the excited condition of the fish.  
         [0006]     There have been attempts to design livewells with cooling systems that circulate water in the livewell that has been chilled to maintain the water temperature in the livewell below the temperature of the natural aquatic habitat of captured gamefish to induce a state of reduced metabolism to prolong the life of the captive gamefish. One such system can be found in U.S. Pat. No. 4,748,765 which provides a livewell for captive gamefish which contains water cooled by circulating the water through an auxiliary ice tank. However, a major drawback to such systems is the need to provide a sufficient quantity of ice to the auxiliary ice tank at the beginning of every fishing trip. In some instances, the supply of ice may not be sufficient to last the duration of the trip to maintain the temperature of the water in the livewell for the duration of the trip. The present invention provides a solution to this problem by providing a livewell that has the water temperature maintained at the reduced temperature by circulating water through a thermodynamic heat exchanger that transfers the heat to a refrigerant that is circulated through a conventional refrigeration cycle commonly found in air conditioning, freezers, and refrigerators. The refrigerant is compressed and circulated by a compressor powered by electricity from the marine vessel&#39;s batteries or electrical power system. Thus, the need for the auxiliary ice tank and ice is eliminated and the water in the livewell can be cooled continuously for an indefinite period.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention provides a livewell for a marine vessel for holding captive gamefish wherein the water temperature maintained in the livewell is maintained at a reduced temperature. The water is cooled by circulating water through a thermodynamic heat exchanger that transfers the heat to a refrigerant that is circulated through a conventional refrigeration cycle commonly found in air conditioning systems, freezers, and refrigerators. The refrigerant is compressed and circulated by a compressor powered by electricity from the marine vessel&#39;s batteries or electrical power system.  
         [0008]     It is an object of the invention to provide a livewell for a marine vessel for holding captive gamefish wherein the water temperature maintained in the livewell is maintained at a reduced temperature.  
         [0009]     It is another object of the invention to provide a livewell for a marine vessel for holding captive gamefish wherein the water temperature maintained in the livewell is maintained at a reduced temperature wherein the water is cooled by passing it through a thermodynamic heat exchanger that is provided cooling by a cooling system that includes a compressor powered by an electrical power source.  
         [0010]     The foregoing and other objects of the present invention will be readily apparent from the following description and the attached drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The invention will now be described, by way of example, with reference to the attached drawings, of which:  
         [0012]      FIG. 1  is a cutaway perspective view of an improved livewell apparatus system installed in the hull of a marine vessel, according to the preferred embodiment of the present invention;  
         [0013]      FIG. 2  is a perspective view of cooling system for the improved livewell apparatus shown in  FIG. 1 , according to the preferred embodiment of the present invention;  
         [0014]      FIG. 3  is an exploded view of the cooling system shown in  FIG. 2 , according to the preferred embodiment of the present invention; and  
         [0015]      FIG. 4  is a schematic diagram of the cooling system of  FIG. 2  operatively connected to the livewell apparatus of  FIG. 1 ; according to the preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]      FIG. 1  is a perspective view of an improved livewell  50 , according to the preferred embodiment of the present invention, shown mounted within the hull  30  of a conventional fishing-type recreational boat  10  and part of a livewell apparatus and control system  55  ( FIG. 4 ). Such boats  10  include a hull  30  and an outer deck  40  horizontally mounted within the interior of hull  30  and extending transversely from one side of the hull  30  to the opposite side. Conventionally, fishing boats  10  of this type have an insulated tank, commonly referred to as a livewell  50 , mounted beneath the outer deck  40  and accessible therethrough by a movable cover or lid  60  ( FIG. 4 ). The livewell  50  is mounted flush below the deck  40  of the vessel and takes up very little space. Operatively connected to the livewell  50  is a chiller assembly  200  conveniently installed under the deck  40  in an out of the way equipment area, saving valuable deck space for other fishing and the like equipment. The chiller assembly  200  (described more fully hereinbelow) provides the cooling needed to cool the water in the livewell  50  to maintain the water temperature in the livewell  50  below the temperature of the natural aquatic habitat of captured gamefish. Alternately, in special circumstances, the water in the livewell  50  may need to be heated in which case chiller assembly  200  heats the water being provided to the livewell  50  until the desired temperature is reached. In this capacity, the chiller assembly  200  operates much like a heat pump wherein the refrigeration cycle is reversed. For convenience purposes, the usage of chiller assembly  200  will be maintained throughout the description although chiller assembly  200  may be used alternately to raise the temperature in the livewell  50 .  
         [0017]     A control module  220  including an on/off switch (not shown) is provided for energizing and de-energizing the chiller assembly  200  and selecting the mode of operation of livewell  50  connected thereto. A wire  280  connects control module  220  to a controller circuit board  370  ( FIG. 4 ). The livewell  50  has a remote temperature sensing device  90  which senses the temperature of the water therein and sends a signal to the controller circuit board  370  ( FIG. 4 ). The controller circuit board  370  ( FIG. 4 ) controls chiller assembly  200  which either heats or cools the water passing therethrough. Water from livewell  50  is received by chiller assembly  200  by supply water piping  100  and returned to chiller  200  by return water piping  101 . A thermodynamic exchanger  320  ( FIG. 4 ) inside chiller assembly  200  removes or adds heat to the water flowing therethrough with a refrigerant that flows through a refrigerant loop  385  ( FIG. 4 ) also located inside chiller assembly  200 . The complete operation of chiller assembly  200  is described more fully hereinbelow.  
         [0018]     Livewell  50  also includes a water level sensing device  490  which senses the level of the water in the livewell  50  and when the water gets to the desired level it sends a signal to the controller circuit board  370  ( FIG. 4 ) to stop the flow of water so that the water does not overfill the livewell  50 . In the event that livewell  50  is overfilled, an overflow inlet  80  ( FIG. 4 ) is provided just above the water level sensing device  490  which further directs overflow water to the lake or ocean via an overflow piping  83  and overflow outlet  461  ( FIG. 4 ). Regular maintenance to make sure this oveflow inlet  80  is not clogged is advisable.  
         [0019]     The livewell  50  is fluidly connected to the chiller assembly  200  by means of a supply water line  100  and a return waterline  101  which circulates the water from the livewell  50  to the chiller assembly  200  to maintain the temperature of the water passing therethrough at the desired temperature. A circulating pump  470  ( FIG. 4 ) is provided for this purpose. A battery  70  provides electrical power to circulating pump  470  ( FIG. 4 ) for circulating the water through chiller assembly  200 . Another pump  440  is provided for circulating water drawn from the lake or ocean  20  ( FIG. 4 ) through a water strainer  450  ( FIG. 4 ) and piping  441  ( FIG. 4 ) into chiller assembly  200  to be used as a cooling medium to cool refrigerant circulating through the refrigerant loop  385  ( FIG. 4 ). After passing through chiller assembly  200 , this water is discharged overboard via a discharge piping  104  and a discharge outlet  460  to the lake or ocean  20  ( FIG. 4 ). Battery  70  also provides electrical power for pump  470  ( FIG. 4 ).  
         [0020]     Referring now to  FIGS. 2 and 3 , shown is a cutaway perspective view and exploded perspective view of the chiller assembly  200 , according to the preferred embodiment of the present invention. The chiller assembly  200  includes a compressor  380 , heat exchangers  390  and  391 , electrical bus  300 , wiring harness  340 , motor-fan assembly  230 , enclosure  210 , high pressure service port  261 , low pressure service port  271 , water outlet  241 , and water inlet  240 . The water supply piping  100  ( FIG. 1 ) is fluidly connected to water inlet  240  and the water return piping  101  ( FIG. 1 ) is fluidly connected to water outlet  241 .  
         [0021]     Referring now to  FIG. 4 , shown is a schematic diagram of the chiller assembly  200  of  FIGS. 2 and 3  operatively connected to the livewell apparatus  50  of  FIG. 1 , according to the preferred embodiment of the present invention.  
         [0022]     The livewell apparatus  50  is operatively connected to chiller assembly  200  via water supply piping  100  and water return piping  101 . In operation, when a desired water temperature is selected at control module  220 , refrigerant such as R-22 or R-134 is circulated through a refrigerant loop  385  in the direction of arrow  500 . Water circulating from livewell  50  is passed through a chiller plate/evaporator  320  to remove heat from the circulated water. As the heat is absorbed by the refrigerant through chiller plate/evaporator  320  the refrigerant begins to change in phase from liquid to a vapor. The low pressure vapor refrigerant moves back to the compressor  380 . The compressor  380  is controlled by a relay  350  activated upon signal from controller circuit board  370 .  
         [0023]     The low pressure vapor refrigerant is compressed to a high pressure and discharged out of the compressor  380 . The refrigerant flows to a first heat exchanger  391  which removes some heat to begin a phase change from a vapor to a liquid. A fan  230  blows air across heat exchanger  391  to remove absorbed heat from the refrigerant. Fan  230  is switched on upon signal from controller circuit board  370 . The refrigerant then flows to a second heat exchanger  390  which gives up absorbed heat to water circulating through the second heat exchanger  390 . The water circulated is drawn from the lake or ocean  20  from a water strainer  450  and circulated through the second heat exchanger  390  before being discharged overboard through a piping  104  and overboard discharge  460  passing through hull  30 . The refrigerant then flows through a filter drier  400  and then a thermal expansion valve  250  which changes the phase of the refrigerant to a low pressure liquid. As the refrigerant again flows through the chiller plate/evaporator  320  and absorbs heat from the water circulated from the livewell  50 , it again begins to change phase from a liquid to vapor. This cycle is repeated until the temperature of the water in the livewell is reduce to the desired selected temperature and compressor  380  and pump  440  are switched off by controller circuit board  370 .  
         [0024]     The battery  70  provides electrical power to the aforementioned electrical components via a positive battery wire  71  and a negative battery wire  72  the battery could be a 12 volt D.C. battery or other voltage battery or the battery could be replaced by some other onboard electrical power source and connected to an electrical power bus  300 . Electrical power is further distributed to the electrical components via a wiring harness  340  ( FIG. 3 ). These are all conveniently installed under the deck in an out of the way equipment area, saving valuable deck space for fishing and other equipment. The controller circuit board  370  is connected to the remotely located control module  220  wherein the operator can select the desired operating mode and temperature to be maintained in the livewell  50  by the chiller assembly  200  and report the current temperature and desired temperature of the water in the livewell  50  to the operator. The controller circuit board  370  also controls circulating pump  440  for circulating water drawn from the lake or ocean through the chiller assembly  200  for providing cooling water for the second heat exchanger  390  in chiller assembly  200 .  
         [0025]     There are three solenoid valves  480 ,  481  and  482  for selectively isolating and fluidly connecting the piping for the cooling water for the first heat exchanger  390  and the livewell  50  to chiller assembly  200  or the overboard discharge piping  83  as required to perform the various functions when the operator selects one of several operating modes at control module  220 . Each of the three solenoid valves  480 ,  481  and  482  valves are operated upon signal from controller circuit board  370 . Specifically, solenoid valve  480  is operated to connect piping  441  from the water strainer  450  to piping  103  connecting the water inlet  240  of chiller assembly so that cooling water flows through the second heat exchanger  390  for cooling purposes. The water then flows through water outlet  241  to piping  104  for discharge via overboard discharge  460 . Likewise, solenoid valves  481  and  482  are operated so that livewell  50  water flows through evaporator  320  to be cooled before being returned via piping  100  to livewell  50 . Alternately, solenoid valve  480  may remain closed so that no water flows through the second heat exchanger  390  so that no cooling water is provided. Water is then free to circulate through to chiller assembly  200  via piping  100  and  101  but no cooling is provided to the circulating water.  
         [0026]     In another mode, solenoid valve  480  is operated to connect piping  441  to piping  442  which is connected to piping  100  so that livewell  50  can be filled with water from the lake or ocean  20 . In this mode, solenoid valve  481  is also operated so that piping  442  is fluidly connected to piping  100 . The pump  440  is energized and will remain energized until water in the livewell  50  reaches the level of the water level sensing device  490 . The overflow inlet  80  and overflow piping  83  are located just above the water level sensing device  490  to prevent overfilling of the livewell  50  above the level of the overflow piping  83 . Regular maintenance is advised to make sure the inlet  80  and the overflow piping  83  is not clogged. Once livewell  50  is filled with water it is ready for operation.  
         [0027]     After prolonged use of livewell  50 , it may be desirable to empty the livewell  50  so it can be cleaned or maintained and fresh water can be replaced in livewell  50 . The emptying of livewell  50  can be performed by using the remote control module  220 . A signal from remote control module  220  operates each of solenoid valves  480  and  481  so that the direction of the flow of water from the livewell  50  is directed through the return water line  101  the recirculating pump  470  the solenoid  482  to the overboard discharge piping  443  and overboard discharge  461  which is mounted in and through the hull  30  of the vessel  10 .  
         [0028]     The chiller assembly  200  includes a compressor  380  to compress the refrigerant gas contained in the refrigerant loop  385 . The refrigerant loop  385  has a high pressure service port  261  and a low pressure service port  271  to service the chiller assembly  200 . The refrigerant through a high pressure switch  421  which can be optionally installed for the safety of the system to shut down should the pressure reach a set high level, as well as a low pressure switch  420  installed for the safety of the system to shut down should the pressure reach a set low level. In an alternate embodiment of the invention, the chiller assembly  200  can operate with either a water cooled condensing coil  390  or an air cooled condensing coil  391  as desired for the particular application and specifications for the system and desired by the user of the system.  
         [0029]     While there have been shown and described herein preferred embodiments of the present invention, it should be apparent to persons skilled in the art that numerous modifications may be therein without departing from the true spirit and scope of the invention. Accordingly, it is intended by the appended claims to cover all such modifications which come within the spirit and scope of this invention.