U.S. patent application number 09/764305 was filed with the patent office on 2001-05-24 for chilled water marine air conditioning.
This patent application is currently assigned to Taylor Made Environmental Systems, Inc.. Invention is credited to Dodge, David A., Harper, James C., Heydt, Mason C., Marciano, Frank A. JR..
Application Number | 20010001363 09/764305 |
Document ID | / |
Family ID | 26803262 |
Filed Date | 2001-05-24 |
United States Patent
Application |
20010001363 |
Kind Code |
A1 |
Dodge, David A. ; et
al. |
May 24, 2001 |
Chilled water marine air conditioning
Abstract
In a marine vessel (such as a yacht or other boat) in the range
of 45-75 feet a chilled water air conditioning system is provided
having a significant advantage over split central systems.
Utilizing two-four water chilling modular units the chilled water
capacity only needs to accommodate about 75-90% of the calculated
BTU heat load for the vessel, while the air handlers are rated at
about 100% of the calculated BTU heat load. Each modular unit has
no refrigerant connection exterior of the casing containing all of
its components, including a condenser coil, evaporator coil,
compressor, reversing valve, and expansion tubing, all operatively
connected to each other by refrigerant lines within the casing.
Chilled water is circulated into and out of the evaporator coil by
an exterior pump and expansion tank operatively connected to each
of the modular units, the chilled water passing through a coil unit
of an air handler. An exterior seawater pump pumps substantially
ambient seawater into the condenser coil and is subsequently
discharged to the exterior of the marine vessel, through its
hull.
Inventors: |
Dodge, David A.; (Boca
Raton, FL) ; Marciano, Frank A. JR.; (Boca Raton,
FL) ; Heydt, Mason C.; (Gulf Stream, FL) ;
Harper, James C.; (Lake Worth, FL) |
Correspondence
Address: |
Nixon & Vanderhye P.C.
8th Floor
1100 N. Glebe Rd.
Arlington
VA
22201
US
|
Assignee: |
Taylor Made Environmental Systems,
Inc.
|
Family ID: |
26803262 |
Appl. No.: |
09/764305 |
Filed: |
January 19, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09764305 |
Jan 19, 2001 |
|
|
|
09409870 |
Oct 1, 1999 |
|
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|
60106067 |
Oct 29, 1998 |
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Current U.S.
Class: |
62/240 |
Current CPC
Class: |
B63J 2/04 20130101 |
Class at
Publication: |
62/240 |
International
Class: |
B63B 025/26 |
Claims
What is claimed is:
1. A marine vessel with a chilled water air conditioning system
comprising: a marine vessel in the range of 45-75 feet, and
including a plurality of different areas to be air conditioned and
having a predetermined high ambient worst case conditions cooling
capacity; an air handler, including a coil unit and a blower,
associated with each of at least some of said different areas;
between two-four water-chilling modular units for cooling water and
circulating the cooled water to said air handler coil units, said
modular units each having a condenser coil and said units
collectively having a condenser cooling capacity between about
75-90% of said predetermined cooling capacity; and a chilled water
pump and expansion tank unit operatively connected to said
water-chilling modular units.
2. A system as recited in claim 1 wherein said water chilling
modular units each comprise a compressor, an evaporator coil, a
reversing valve, and expansion tubing in addition to said condenser
coil, connected together by refrigerant lines.
3. A system as recited in claim 2 wherein said condenser coil,
compressor, reversing valve, evaporator coil, and expansion tubing
are disposed within substantially the same casing, and are mounted
on a drain pan.
4. A system as recited in claim 3 further comprising four hose
connections for said casing, two of said hose connections
operatively connected to said condenser coil and connected by a
hose to a seawater pump and an overboard discharge of said marine
vessel, and two of said connections operatively connected to said
chilled water pump and an air handler coil unit; and wherein no
refrigerant line extends exteriorly of said casing.
5. A system as recited in claim 4 further comprising solid state
electronics for operating said modular units so that which of said
plurality of units is running at any point in time when less than
full capacity of said collective units is necessary is rotated.
6. A system as recited in claim 3 wherein each of said units has a
capacity of about 16,000 BTU's per hour, about 20,000 BTU's per
hour, or about 24,000 BTU's per hour.
7. A system as recited in claim 6 wherein each of said units has a
depth of between about 17-19 inches, a width between about 10-14
inches, and a height of between about 10-17 inches.
8. A system as recited in claim 1 further comprising solid state
electronics operatively connected to said modular units having
freeze-stat protection and an associated sensor.
9. A system as recited in claim 1 further comprising a solid state
control with a digital readout providing temperature and diagnostic
information.
10. An assembly as recited in claim 9 wherein said solid state
control includes as inputs a high refrigerant pressure switch, a
chilled water flow switch, and a return water sensor.
11. A chilled water air conditioning module comprising: a casing
having a power line extending therefrom and a plurality of water
transporting hose connections in the exterior thereof, said casing
being devoid of any refrigerant lines extending in or out thereof;
a compressor, condenser coil, evaporator coil, reversing valve, and
expansion tubing provided within said casing, including refrigerant
lines extending therebetween; and two of said water transporting
connections operatively connected to said condenser coil, and two
of said connections operatively connected to said evaporator coil,
said evaporator coil circulating chilled water therein and chilling
the water circulating therein.
12. A water-chilling modular unit as recited in claim 11 wherein
said casing is mounted on a drain pan to receive condensate from
components within said casing.
13. A water-chilling modular unit as recited in claim 11 wherein
each of said units has a capcity of about 16,000 BTU's per hour,
about 20,000 BTU's per hour, or about 24,000 BTU's per hour.
14. A water-chilling modular unit as recited in claim 11 wherein
each of said units has a depth of between about 17-19 inches, a
width between about 10-14 inches, and a height of between about
10-17 inches.
15. A water-chilling modular unit as recited in claim 11 further
comprising a high refrigerant pressure switch within said casing
operatively connected to a refrigerant line between said compressor
and said reversing valve.
16. A water-chilling modular unit as recited in claim 11 wherein
pumps for circulating water through said water transporting
connections are mounted exteriorly of said casing, and no water
circulating pump is mounted interior of said casing.
17. A water-chilling modular unit as recited in claim 11 further
comprising a solid state control mounted exteriorly of said casing,
said solid state control including freeze-stat protection and a
supply water temperature monitor, and a digital readout providing
temperature and diagnostic information.
18. A method of air conditioning a marine vessel in the range of
45-75 feet and including a plurality of different areas to be air
conditioned and having a predetermined high ambient worst
conditions cooling capacity using a chilled water air conditioning
system and an air handler, including a coil unit and a blower,
associated with each of at least some of the different areas to be
air conditioned, said method comprising: (a) connecting up between
two-four water chilling modular units for cooling water and
circulating the cooled water to the air handler coil units, each
modular unit including a condenser coil and an evaporator coil
within the marine vessel, the modular units collectively having a
condenser cooling capacity between about 75-90% of the
predetermined cooling capacity; and (b) circulating substantially
ambient water from exteriorly of the marine vessel to the condenser
coil and ultimately discharging the circulated water from the
condensing coil to the exterior of the vessel.
19. A method as recited in claim 18 wherein (a) is practiced
utilizing water-chilling modular units each having a cooling
capacity of between about 16,000-24,000 BTU's.
20. A method as recited in claim 19 further comprising: operating
less than all of the water-chilling modular units during low
cooling load conditions while operating at least one of the
water-chilling modular units; and rotating which of the
water-chilling modular units are operated or not operated during
low cooling load conditions.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon provisional application
Serial No. 60/106,067 filed Oct. 29, 1998.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The invention relates to a system and method to provide air
conditioning in marine environments. While chilled water systems
have been used in large commercial buildings and as the standard on
very large yachts (over 80 feet), up until now central systems have
been the only cost effective solution for cooling of yachts/marine
vessels in the range of 45-75 feet, since the cost of chilled water
systems has been prohibitive in this size boat. According to the
invention it is possible to use modular units to provide chilled
water for marine air conditioning, each unit having a cooling
capacity of between 16,000-24,000 BTU's so that one unit may be
used, or two through four units may be connected together, to
effectively (both from the functional standpoint and cost
effectively) cool boats in the range of 45-75 feet. The invention
is particularly useful for vessels (such as 45 foot boats) which
require a 36,000 BTU or greater capacity, with multiple condensing
units and air handlers. The chilled water air conditioning system
according to the present invention has reduced BTU requirements for
the condensing units, no refrigerant line sets, enhanced balanced
temperature control throughout the vessel, system energy
management, and compressor redundancy to eliminate down time, as
well as ease of serviceability.
[0003] As with all types of air conditioning systems, BTU load
calculations must first be done on any vessel to be air-conditioned
to ensure that the equipment selected can provide adequate heating
or cooling for all applicable areas. With split central equipment
there must be a one for one match of evaporator air handlers to
condensing units. In other words, if a vessel requires 62,000 BTU's
of air conditioning one must specify 62,000 BTU's of evaporator air
handlers and 62,000 BTU's of central condensing. Normally one will
have one condensing unit for each evaporator, in some cases one can
have smaller evaporators matched to one condensing unit (i.e. one
24,000 BTU condenser can run 2.times.12,000 BTU evaporators).
[0004] Chilled water equipment, as according to the invention, has
a significant advantage over split central systems in that only the
air handlers must equal the calculated BTU heat load for the
vessel, whereas the chilled water power plant only needs to
accommodate 75-90% of the calculated BTU heat load. In the above
example, 62,000 BTU of air handlers only requires 46,500-55,800
BTU's of chiller capacity. The size of the vessel, number of air
handlers, and equipment selected determines the percentage of
capacity required. Experience indicates that under nominal
conditions a chiller plant operates at 50% or less of its capacity
because of its automatic energy management feature.
[0005] With split central systems one may have only one thermostat
control per central condensing unit to control both the condensing
unit and the evaporator. Thus, if one has multiple evaporators on
one condensing unit, a slave fan speed only control can be used on
the slave evaporators, which may not coincide with the end user's
preferences. The fan on the second evaporator must always run
otherwise, icing can occur resulting in liquid return to the
compressor potentially damaging the condensing unit.
[0006] With a chilled water system ail air handler controls are
totally independent from the chiller controls. The chiller has its
own energy management system which automatically stages compressors
on and off to control water temperature. Each air handler may have
individual controls or up to four air handlers can be driven from a
single control typically in a large common area. That is,
temperature control is totally flexible throughout the vessel.
[0007] Installation of split central air conditioning systems
requires that an EPA certified technician handle the refrigerant
line sets. This is a government regulation imposed to ensure that
the R-22 refrigerant used in the system does not escape into the
atmosphere. This is a problem for most boat builders as it limits
the number of people qualified to install split central equipment
in manufacturing. Many boat builders have chosen to contract this
work out and as a result can be a logistics problem in
manufacturing. Done correctly, the process of attaching refrigerant
line sets, evacuating the system, charging the system, finding and
repairing leaks in flair fittings and finally balancing the system
to ensure the proper refrigerant charge exists for optimum
performance is very time consuming and costly for any production
boat builder. In reality, due to customer delivery pressures much
of this process is rushed, resulting in poor performance of the
system in the field often creating warranty and long term
reliability problems. Also, because boats, unlike fixed building
structures, flex while underway, mechanical refrigerant line set
fittings are constantly under stress often resulting in
intermittent refrigerant leaks.
[0008] Since a chilled water system has a self-contained factory
sealed refrigerant system, there are no refrigerant line sets to be
installed in the vessel. Therefore, there is no need for an EPA
certified technician to perform any installation or system
balancing upon startup. The self-contained chiller condensing unit
is plumbed to the air handlers via insulated water lines, which is
something boat builders are most familiar with. Installing chilled
waterlines is as simple as linking a pump, and expansion tank with
fill valve, to a closed plumbing loop. Pipe and insulation sizing
can be read off of a simple chart and installed by anyone with
basic plumbing skills, simplifying the manufacturing process. When
the installation is complete, the installer fills the system with
fresh water and uses built in air bleeders to purge air from the
lines. Then one merely turns on the chiller and sets the air
handler thermostats.
[0009] Split central systems operate completely independent of one
another. This concept has worked well in many applications and
gives the end user desired individual climate control, however,
there are some drawbacks.
[0010] 1. Because the thermostats are independent they can easily
oppose each other because of air spill over from one area to
another. Since each thermostat controls a condensing unit this
causes short cycling of compressors leading to premature
failure.
[0011] 2. If a condensing unit fails, there is no redundancy, and
the section of the boat which relies on that unit for cooling will
not have cooling until the unit is repaired.
[0012] 3. There is no energy management between the condensing
units. They turn on and off independently, and therefore they can
be on or off at any given point in time regardless of the total
overall heat load on the boat. Only the independent thermostats
control the individual compressors.
[0013] Although chilled water system air handlers operate
independently, they are all tied to the same parallel chilled water
loop which is fed back to the chilled water condensing units
allowing the compressors to cycle on and off based upon the heat
load on the total water loop. Because each air handler is tied into
one chilled water loop the total heat load is integrated into one
system which is the basis for energy management of the condensing
units. The fact that the air handlers are independent allows for
desired independent thermostatic control without creating
compressor short cycling conditions because the chilled water
condensers react to the total balanced load of the chilled water
loop.
[0014] Each air handler removes heat from the cabin space and
transfers the heat into the cold chilled water loop. As air
handlers turn on and off, the average temperature returning in the
closed loop to the chiller condensers rises or falls. The chiller
condensing system senses the temperature of the water and turns
compressors on and off based upon the overall total heat load of
the boat. The change in temperature of the water is very gradual
since the volume of water contains stored energy, which acts as an
energy buffer. This gradual change eliminates short cycling of the
compressors therefore increasing the useful life of the system and
eliminates those initial cold blasts of air associated with typical
direct expansion start-ups.
[0015] The chilled water condensers only need enough capacity for
75-90% of the total heat load calculations of the boat. Since heat
load calculations are typically based on high ambient worst case
conditions, the only time full capacity is needed is for a warm
start up. Under normal operation, 50% of the total cooling capacity
is usually more than enough to remove heat from all areas of the
boat. This is why 75-90% downsizing of chilled water condensers as
compared to total worst case heat load requirements is practical in
all applications.
[0016] Chilled water systems normally comprise two or more modular
condensing units (hence the 36,000 BTU minimum discussed above)
which have independent sealed compressor systems creating complete
operational redundancy. This means that if a chilled water
condensing unit malfunctions for any reason the other operating
condensing unit(s) will continue to remove heat from the chilled
water loop, which provides cooling to the entire vessel. Since 50%
capacity is normally all that is required of a system operating in
nominal conditions, the end user has time to facilitate repairs
without being inconvenienced.
[0017] Mechanical breakdowns in a split central system require an
EPA certified technician to troubleshoot and repair the system. In
case of compressor's failure, the entire system needs to be
evacuated and removed for replacement or repair. During this
process the end user may be seriously inconvenienced as discussed
above. Upon replacement, the entire sealed system must be
evacuated, recharged and balanced for proper operation. This can be
a costly and time-consuming process, not to mention the possibility
of a poor flare fitting or a loose flare.
[0018] Since a chilled water system has redundant components, a
component or compressor failure rarely results in inconvenience to
the end user. Although some repairs will require an EPA certified
technician, the end user can choose to remove the self-contained
sealed unit and replace it in a matter of hours or send it to an
authorized service center for repairs. Removal of a modular chilled
water condensing unit simply requires disconnecting and capping off
the water lines and disconnecting the electrical supply.
Installation of the new or repaired unit requires connecting water
lines, bleeding out the air and reconnecting the electricity.
[0019] The location of the modular condensing unit according to the
invention should be dry and accessible for service. The condensing
unit should be secured to a level horizontal surface with brackets.
The brackets hold the weight of the equipment as well as handle any
torsional movement. Each condensing unit must be independently
supported, not stacked directly on top of each other.
[0020] Also according to the invention reinforced marine grade hose
is to be used for the seawater circuit. The hose is to be routed
upwards from the thru-hull intake to the condensing unit to prevent
air locks in the centrifugal seawater pump. Circulation connections
between the condensing unit and chilled water lines are to be made
with properly sized fittings and reinforced marine grade hose. All
hose connections are to be double clamped. Ball valves should be
installed at chilled water inlet/outlet of each unit and each air
handler for overall serviceability of system. All hose and fittings
should be properly insulated upon completion of leak tests to
prevent condensation and energy or capacity loss. The condensing
unit chassis for each modular unit has an integral condensation
drain pan for removal of any water that may form. A hose should be
secured to this drain pan spud and routed downward to a proper sump
or overboard discharge outlet.
[0021] The air conditioner air handier is never installed in bilge
or engine room areas. It is important to insure that the selected
location is sealed from direct access to bilge and/or engine room
vapors. Condensate drain lines should not be terminated within four
feet of any outlet of engine or generator exhaust systems, nor in a
compartment housing an engine or generator, nor in a bilge (vapors
can travel up the drain line), unless the drain is connected
properly to a sealed condensate or shower sump pump. Failure to
comply may allow bilge or engine room vapors to mix with the air
conditioners return air and contaminate living areas.
[0022] All circuit breakers and wire gauge must be sized according
to marine design standards. Only stranded tinned copper wire should
be used. All wiring should be routed through strain-relief
connectors provided in the electrical boxes.
[0023] All equipment should be properly grounded using grounding
lugs provided on each unit's chassis. Electrical boxes are
pre-wired for power and control circuits. Mechanical control panels
can be remote mounted in a convenient location, using four mounting
screws. Field wiring is required between remote switch and unit
electrical box.
[0024] All chilled water condensing units according to the
invention use closed-refrigerant circuits, precharged with R-22
refrigerant, hermetically sealed, and factory tested and certified.
No additional refrigerant is required during the installation or at
initial start-up-and operation of the system. In keeping with
regulations set forth by the EPA, only certified technicians should
perform service on, or make adjustments to, any refrigerant
circuit.
[0025] The system according to the invention functions as follows:
During the off-peak requirement times a single compressor would
handle the air conditioning load on its own, and only requires a
second compressor to kick in if the first is not able to adequately
chill the water based upon the ambient temperature. This is
important especially in relation to shore power and/or generation
on-board. With current competitive systems, due to the fact that
the compressors cycle together, they require a much larger power
draw and one might have to run a generator overnight to meet the
electrical demand. Not only is this a noise pollution problem, but
also the carbon monoxide produced from the exhaust to the generator
is a potential life hazard. With the system of the invention, since
a single compressor will handle the load in the off-peak times
(i.e. late evening, overnight, early morning), there is no need for
additional power other than the typical shore power hook-up (30
amp). One benefit of this is that the boater uses the power he/she
paid for with the docking, instead of the fuel for the generator.
It should also be noted that in order to achieve long life of the
system components, the compressors may be programmed to cycle/run
in "rotation" so that the same compressor is not the one running
each time a single compressor handles the load.
[0026] The installation of the modular units of the invention, each
of which is basically a "shoebox" which looks very simple and
nondescript, requires substantially only hook-up of power and four
hoses (two saltwater (intake and discharge) and two for fresh water
feed and return lines to the air handlers). In addition, the
control panel/unit is preferably completely solid state for ease of
use, and operation.
[0027] The modular units according to the invention may be provided
in a plurality of sizes. For example there may be three sizes,
16,000 BTU/H, 20,000 BTU/H, and 24,000 BTU/H (cooling capacity).
The 24,000 BTU/H units may use scroll compressors, while the other
units use rotary compressors. The condenser coil may be constructed
of spiral fluted cupronickel to provide maximum heat transfer and
high corrosion resistance. The 16,000 BTU/H units typically have a
depth of between 17-19 inches (e.g. about 18 inches), a width of
about 10-13 inches (e.g. about 111/2inches) and a height of between
about 10-13 inches (e.g. about 11.25 inches). The 20,000 BTU/H
units have the same depth and width but with a height of between
about 12-15 inches (e.g. about 13.5 inches). The 24,000 BTU/H units
may have the same depth but a width of between about 12-14 inches
(e.g. about 13 inches) and a height of between about 14-17 inches
(e.g. about 15.75 inches).
[0028] According to one aspect of the present invention a marine
vessel (such as a yacht or other boat) with a chilled water air
conditioning system is provided comprising: A marine vessel in the
range of 45-75 feet, and including a plurality of different areas
to be air conditioned and having a predetermined high ambient worst
case conditions cooling capacity. An air handler, including a coil
unit and a blower, associated with each of at least some of the
different areas. Between two-four water-chilling modular units for
cooling water and circulating the cooled water to the air handler
coil units, the modular units each having a condenser coil and the
units collectively having a condenser cooling capacity between
about 75-90% of the predetermined cooling capacity. And a chilled
water pump and expansion tank unit operatively connected to the
water-chilling modular units.
[0029] The system according to the invention also includes the
following aspects: The water chilling modular units each comprise a
compressor, an evaporator coil, a reversing valve, and expansion
tubing in addition to the condenser coil. The condenser coil,
compressor, reversing valve, evaporator coil, and expansion tubing
are disposed within substantially the same casing, and are mounted
on a drain pan. Four hose connections are provided for the casing,
two of the hose connections are operatively connected to the
condenser coil and connected by a hose to a seawater pump and an
overboard discharge of the marine vessel, and two of the
connections are operatively connected to the chilled water pump and
an air handler coil unit. Solid state electronics for operating the
modular units are provided so that which of the plurality of units
is running at any point in time when less than full capacity of the
collective units is necessary is rotated. Each of the units
preferably has a capacity of about 16,000 BTU's per hour, about
20,000 BTU's per hour, or about 24,000 BTU's per hour. Each of the
units preferably has a depth of between about 17-19 inches, a width
between about 10-14 inches, and a height of between about 10-17
inches. The solid state electronics preferably comprises
freeze-stat protection and an associated sensor, a solid state
control with a digital readout providing temperature and diagnostic
information and as inputs a high refrigerant pressure switch, a
chilled water flow switch, and a return water sensor.
[0030] According to another aspect of the present invention a
water-chilling modular unit for air conditioning a marine vessel is
provided. The unit comprises: The casing having a power line
extending therefrom and a plurality of water transporting hose
connections in the exterior thereof, the casing being devoid of any
refrigerant lines extending in or out thereof. A compressor,
condenser coil, evaporator coil, reversing valve, and expansion
tubing provided within the casing, including refrigerant lines
extending therebetween. Two of the water transporting connections
operatively connected to the condenser coil, and two of the
connections operatively connected to the evaporator coil, the
evaporator coil circulating chilled water therein and chilling the
water circulating therein.
[0031] The water-chilling unit according to the invention also
includes: A casing is mounted on a drain pan to receive condensate
from components within the casing. Each of the units has a capacity
of about 16,000 BTU's per hour, about 20,000 BTU's per hour, or
about 24,000 BTU's per hour. Each of the units has a depth of
between about 17-19 inches, a width between about 10-14 inches, and
a height of between about 10-17 inches. A high refrigerant pressure
switch is preferably operatively connected to a refrigerant line
between the compressor and the reversing valve. Pumps for
circulating water through the water transporting connections are
mounted exteriorly of the casing, and there is no water circulating
pump mounted interior of the casing. A solid state control mounted
exteriorly of the casing includes freeze-stat protection and a
supply water temperature monitor, and a digital readout providing
temperature and diagnostic information.
[0032] According to yet another aspect of the present invention
there is provided a method of air conditioning a marine vessel
(such as a yacht or other boat) in the range of 45-75 feet and
including a plurality of different areas to be air conditioned and
having a predetermined high ambient worst conditions cooling
capacity, using a chilled water air conditioning system and an air
handler, including a coil unit and a blower, associated with each
of at least some of the different areas to be air conditioned. The
method comprises: (a) Connecting between two-four water chilling
modular units for cooling water and circulating the cooled water to
the air handler coil units, each modular unit including a condenser
coil and an evaporator coil within the marine vessel, the modular
units having collectively a condenser cooling capacity between
about 75-90% of the predetermined cooling capacity; and (b)
circulating substantially ambient water from exteriorly of the
marine vessel to the condenser coil and ultimately discharging the
circulated water from the condensing coil to the exterior of the
vessel.
[0033] In the method preferably (a) is practiced utilizing
water-chilling modular units each having a cooling capacity of
between about 16,000-24,000 BTU's, and the method further comprises
operating less than all of the water-chilling modular units during
low cooling load conditions while operating at least one of the
water-chilling modular units, and rotating which of the
water-chilling modular units are operated or not operated during
low cooling load conditions.
[0034] It is the primary object of the present invention to effect
air conditioning of a marine vessel, particularly in the 45-75 foot
size, utilizing a chilled-water system, which is advantageous
compared to conventional split central systems. This and other
objects of the invention will become clear from an inspection of
the detailed description of the invention and from the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a top schematic perspective view of an exemplary
modular chilling unit according to the present invention;
[0036] FIG. 2 is a top view of the unit of FIG. 1;
[0037] FIG. 3 is a side view of the unit of FIG. 1;
[0038] FIG. 4 is a front end view of the unit of FIG. 1;
[0039] FIG. 5 is a schematic perspective view showing the
utilization of one of the units of FIG. 1 in association with two
air handler assemblies, it being understood that typically two-four
units like that in FIG. 1 are utilized in a 45-75 foot boat, and
more than two air handlers may be utilized;
[0040] FIG. 6 is a schematic illustration of the interior
components of the unit of FIG. 1; and
[0041] FIG. 7 is an electrical schematic relating to the operation
of the unit of FIG. 1 in the system of FIG. 5.
DETAILED DESCRIPTION OF THE DRAWINGS
[0042] A water-chilling modular unit according to the invention is
shown generally by reference numeral 10 in the drawings, and
includes an outer sheet metal casing or housing 11 typically having
the dimensions as discussed above, with an electrical box 12 on
top. The box 12 is connected up to a suitable source of electrical
power. FIGS. 3 and 4 illustrate exemplary dimensions of the unit
10. The housing 11 is mounted on a drain pan 13 which has a
plurality of knock-out plugs/alternative outlet connections 14 for
condensate draining. Unit 10 includes a seawater inlet/hose
connection 15, a seawater outlet/hose connection 16, a chilled
water inlet/hose connection 17, and a chilled water outlet/hose
connection 18, all preferably provided on the same face of housing
11 as illustrated in FIGS. 1 through 4; no refrigerant lines are
exterior of the casing 11.
[0043] FIGS. 3 and 4 illustrate various dimensions A-E that may be
utilized for an exemplary modular unit 10 according to the
invention. While the dimensions will vary depending upon the size
of the modular unit 10 (e.g. depending upon whether it has a 16,000
BTU/H, 20,000 BTU/H, 24,000 BTU/H, or some other size, cooling
capacity), the dimension A may be about eleven inches, the
dimension B about thirteen inches, the dimension C about thirteen
and a half inches, the dimension D about eighteen inches, and the
dimension E about eleven and a half inches, for a 20,000 BTU/H
unit. A 16,000 BTU/H unit would have the same depth D and width E
but a height C of between about ten-thirteen inches (e.g. about
11.25 inches), whereas a 24,000 BTU/H unit would have the same
depth D but a width E between about twelve-fourteen inches (e.g.
about thirteen inches) and a height C between about
fourteen-seventeen inches (e.g. about 15.75 inches).
[0044] The internal components of the unit 10, inside the housing
11, are illustrated schematically in FIG. 6. The operative
components preferably comprise a high efficiency compressor 20,
such as a Tecumseh rotary compressor or a Copeland scroll
compressor, connected to a conventional tube-in-tube spiral fluted
evaporator coil 22, and a cupronickel condenser coil 23.
Connections are done by conventional conduits as illustrated in
FIG. 6 for transporting refrigerant (preferably R-22) in a
conventional manner. A reversing valve 24 is also provided, as well
as expansion tubing--shown only schematically at 25 in FIG. 6. FIG.
6 shows the refrigerant lines 26-31 connected to the operative
components with flow in reverse cycle (that is the cooling mode).
The flows are reversed for heating, as is conventional. Fresh water
flows in the lines (17, 18) and through the evaporator 22, the
coldest water being discharged from outlet 18 through line 32 to
the air handlers 33, with a return line 34 through a pump and
expansion tank unit 35, in turn connected via line 36 to the
chilled water inlet 17. The lines and units 20-31 all have
refrigerant--such as R-22--flowing therethrough and are
hermetically sealed within the housing 11 so that no connection of
refrigerant to any external system is necessary. All of the lines
and units exterior of the housing 11 simply handle water.
[0045] FIG. 5 illustrates a system, shown generally by reference
numeral 40, according to the invention with only one unit 10 being
shown in solid line for simplicity, however it is understood--as
illustrated by the dotted lines 41 in FIG. 5--that other units 10
(typically one-three additional units 10) are connected to the
system 40 to typically provide between two and four units 10.
[0046] The condensate drain from the condenser 23 in each unit 10
is directly into the pan 13, in open communication therewith, and
is eventually connected by a hose 42 to an ultimate conventional
drain (not shown).
[0047] FIG. 5 shows the conventional seawater pump 43 connected
through a seawater strainer 44 and a conventional shut-off valve 45
to a thru-hull fitting 46 (e.g. a clam shell scoop) penetrating the
hull 47 of a 45-75 foot boat. The seawater pump 43 is connected via
the conduit 48 to the inlet 15, while the outlet 16 is connected
via the conduit 49 to a conventional overboard discharge 50 in the
hull 47. The conventional air handler assemblies 33 for cooling the
cabin space of the marine vessel each preferably include a coil
unit 52 through which the chilled water in line 32 flows, and a
blower 53 which blows air past the cooling coil 52 into the cabin
space to be air conditioned on the boat having the hull 47. Each of
the units 33 may have a return air grill with filter 54, and the
cooled air passes through a flexible duct 55 to a conventional
transition box and supply air grill 56. While two handlers 33 are
illustrated in FIG. 5, for cooling two different cabin spaces, more
than two air handlers 33 may be provided, each connected via a
conventional water-tight connection 58 to the pipes 32, 34.
Typically each air handler 33 also has a condensate drain 59.
[0048] The unit 35, which includes a chilled water pump and an
expansion tank, typically has substantially the same dimensions as
a unit 10, with multiple inlets and outlets for connection to
two-four units 10, as schematically illustrated for two such units
10 in FIG. 5. A condensate drain 60 is also typically associated
with unit 35, and it has a conventional fill valve 63, and a
conventional water pressure gauge 64 , as seen schematically in
FIG. 5. Conventional manually (or automatically) operated ball
valves 65 are also typically used in water lines as needed; for
example in the positions illustrated in FIG. 5.
[0049] FIG. 7 schematically illustrates an electrical schematic
showing the interconnection between the various components of the
system 40 to provide effective control thereof. Typically a master
control switch--illustrated schematically at 62 in FIGS. 5 and
7--is provided to control the system 40, each electrical box 12
typically including only solid state components.
[0050] The solid state control, shown generally at 67 in FIG. 7,
for the chiller system 10 monitors the return water temperature and
controls the operation of the compressor 20 based on the set point.
The heat and cool mode are selected by the control switch 62. The
supply water temperature is monitored by sensor 68 to ensure the
temperature does not exceed the limits of the equipment. The high
pressure switch 69 is monitored to ensure a high refrigerant
pressure fault does not harm the equipment. Built in time delays
allow for staging of multiple units. The heat and cool set points
are adjusted on the circuit board. A digital readout 70 provides
temperature and diagnostic information.
[0051] For the solid state circuitry 67, typically 220 volt
operation is provided, although 115 volt operation may be available
by changing the upper strapping on the transformer connected to the
unit 67. The inputs to the unit 67 include the high refrigerant
pressure switch 69 (which may also have inherent low freon pressure
sensing, which is connected to the additional contact illustrated
at 74 in FIG. 7, when utilized), a chilled water flow switch 72
located at an appropriate location within the chilled flow, return
water sensor 73, the sensor 68 (which includes independent
freeze-stat protection), and high water limit protection
switch/gauge 64, connected where appropriate to the unit 67.
[0052] The switch 62 switches between the cooling mode, heating
mode, and off mode, and may comprise any conventional switch for
the purpose. The freeze stat protection associated with the sensor
68 preferably is set to open at 38.degree.F. and close at
50.degree. F. (and is ignored in the heating mode). The high
temperature limit typically opens at 125.degree. F. and closes at
120.degree. F., and is ignored in the cool mode.
[0053] The control unit 67 preferably is equipped with four
conventional "Bimini Jumpers" (one shown schematically at 76 in
FIG. 7) which allow any or all of the relay outputs to be forced on
for troubleshooting or emergency operation.
[0054] The components of the solid state control 67 are preferably
provided so as to provide the following operation:
[0055] When the main circuit breaker (not shown, connected to the
"AC Power Inputs") is turned on, the display 70 will display the
revision code for five seconds. The display 70 will go blank for
one second and remain blank if the mode switch 62 is "off". If the
system is heating or cooling, the display 70 will indicate the
return water temperature (as sensed by the sensor 73). The unit 67
will operate according to the preset temperature and staging
delays.
[0056] The unit 67 will operate the unit 10 to cool when the mode
switch 62 is in "cool" position, and the return water temperature
is 2.degree. F. more than the cool set point. The freeze stat (68)
and flow switch (72) circuits must be closed. The high limit is
ignored in the cooling mode.
[0057] The control unit 67 will control the unit 10 to heat when
the mode switch 62 is in the "heating" mode, and the return water
temperature is 2.degree. F. lower than the heat set point. The flow
switch 72 circuit must be closed. The freeze stat (68) is ignored
in this mode.
[0058] No cycle will be started if the return water sensor 73 is
open, or if the freeze stat 68 and flow switch 72 circuits are
open. The chilled water pump 35 operates substantially continuously
when the unit is in the heat or cool mode. The seawater pump 43
turns on one minute before the compressor 20 starts and turns off
one minute after the compressor 20 cycle is completed. The valve 24
is toggled to relieve head pressure if the previous cycle ended
within 75 seconds of a new cycle, and the valve 24 is also toggled
when the unit is powered up from the circuit breaker.
[0059] The return water temperature is set with the system "on" by
adjusting the cool trim variable resistor, the actuator 78 thereof
being seen in FIG. 7. The selected temperature will appear on the
display 70 and remain visible while the cool point is adjusted by
turning the actuator 78. The setting will remain on the display 70
for five seconds after the adjustment is completed. The cooling set
point range is preferably between about 40-55.degree.F. The same
procedure is followed for setting the heating set point, using the
actuator shown schematically at 79 in FIG. 7 for adjusting the
heating variable resistor. The heating range set point is
preferably between about 100-120.degree. F.
[0060] The staging delay is also set, when the unit 67 (the switch
62) is either in the "heat" or "cool" mode. The staging trim point
is adjusted by adjusting the actuator shown schematically at 80 in
FIG. 7 for the staging pot, until the desired compressor staging
delay appears on the display 70. Staging delay will remain in the
display 70 for five seconds after the adjustment is completed. The
staging adjustment range is preferably between about 10-110
seconds.
[0061] If desired the unit 67 can display in degrees Celsius
instead of Fahrenheit by moving the F/C jumper 81 from the lower to
upper position when the power is off. Also fault displays may be
provided in the display 70 such as "high freon pressure", "low
freon pressure", "chilled water flow switch", "freeze stat",
"return sensor", or "high water limit" when a fault is indicated by
one of the units 64, 68, 69, 72, or 73. For the fault handling
protocol, at the end of the staging delay the unit 67 will restart
if all the faults have been cleared. If a low freon pressure switch
is installed (e.g. using contact 74), the low freon jumper 82 must
be cut. The low freon pressure fault preferably has a ten minute
delay. When a fault occurs the staging delay is initiated, and the
appropriate display is flashed in the unit 70. If three faults
occur before the cycle is completed lockout will occur. Operation
may be restored by correcting the fault and resetting the unit 67
with the mode switch 62 or by turning the AC power off and on (as
by using a circuit breaker connected to the "AC power input" in
FIG. 7). The mode switch 62 is then reset by turning if off and
then back to the heat or cool mode, respectively.
[0062] It will thus be seen that according to the invention an
effective, and cost effective, series of modular cooling units are
provided associated with a marine vessel air conditioning system
which uses chilled water--and has the inherent advantages
associated therewith--to cool boats typically in the 45-75 foot
range. It should be understood that many modifications may be
provided according to the invention, including the substitution of
conventional equivalents for each of the components described
above. Also, for each of the ranges given above all smaller ranges
within a broad range are also specifically provided herein.
Therefore the invention is to be accorded the broadest
interpretation possible, limited only by the prior art, to
encompass all equivalent structures and methods.
* * * * *