U.S. patent application number 11/500005 was filed with the patent office on 2006-12-28 for modular tankless water heater.
Invention is credited to Kevin Hay, Gregg C. Johnson, Thomas J. Shortland, William R. Sturm, Joseph M. Sullivan.
Application Number | 20060291838 11/500005 |
Document ID | / |
Family ID | 36318225 |
Filed Date | 2006-12-28 |
United States Patent
Application |
20060291838 |
Kind Code |
A1 |
Sturm; William R. ; et
al. |
December 28, 2006 |
Modular tankless water heater
Abstract
A tankless water heater module is disclosed and includes a
casing having a first end, a second end and a plurality of conduits
formed therein. A top head manifold is coupled to the first end of
the casing and includes a port aligned with each of the plurality
of conduits. A bottom head manifold is coupled to the second end of
the casing and includes a port aligned with each of the plurality
of conduits. An immersion heating element extends through each port
of the top head manifold and into the conduit aligned therewith. A
flow path extends through the plurality of conduits, the plurality
of conduits coupled in fluid communication by channels between
ports of the top head manifold and a channel between ports of the
bottom head manifold.
Inventors: |
Sturm; William R.; (Tempe,
AZ) ; Sullivan; Joseph M.; (Gilbert, AZ) ;
Shortland; Thomas J.; (Tempe, AZ) ; Hay; Kevin;
(Fountain Hills, AZ) ; Johnson; Gregg C.; (Peoria,
AZ) |
Correspondence
Address: |
ROBERT A. PARSONS
4000 N. CENTRAL AVENUE, SUITE 1220
PHOENIX
AZ
85012
US
|
Family ID: |
36318225 |
Appl. No.: |
11/500005 |
Filed: |
August 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11360124 |
Feb 23, 2006 |
7088915 |
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11500005 |
Aug 7, 2006 |
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11080300 |
Mar 15, 2005 |
7046922 |
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11360124 |
Feb 23, 2006 |
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Current U.S.
Class: |
392/482 |
Current CPC
Class: |
F24H 1/102 20130101;
F24H 9/2028 20130101 |
Class at
Publication: |
392/482 |
International
Class: |
F24H 1/10 20060101
F24H001/10 |
Claims
1. A modular tankless water heater system comprising: a power
module coupled to a power source; a water heater module including a
casing having a first end, a second end, and a plurality of
conduits formed therein, extending from the first end to the second
end, a top head manifold coupled to the first end of the casing and
including a port aligned with each of the plurality of conduits, a
bottom head manifold coupled to the second end of the casing
including a port aligned with each of the plurality of conduits, an
immersion heating element extending through each port of the top
head manifold and into the conduit aligned therewith, each
immersion heating element coupled to the top head manifold, and a
flow path from through the plurality of conduits, the plurality of
conduits coupled in fluid communication by channels between ports
of the top head manifold and between ports of the bottom head
manifold a relay switch coupled to each immersion heating element
and to the power module; and a control unit receiving fluid flow
data and fluid temperature data from the water heater module,
coupled to the relay switches for actuating the relay switches upon
selected fluid flow and fluid temperature data.
2. A system as claimed in claim 1 wherein the power module includes
a terminal and breaker switch for each heating element.
3. A system as claimed in claim 1 wherein each relay switch is
mounted to the casing.
4. A system as claimed in claim 1 further including an inlet water
temperature sensor carried by the water heater module, an outlet
water temperature sensor carried by the water heater module, and a
flow sensor carried by the water heater module, the inlet water
temperature sensor, the outlet water temperature sensor, and the
flow sensor each coupled to the control unit.
5. A system as claimed in claim 1 further including a second water
heater module coupled in series to the water heater module and to
the control unit and power module.
6. A system as claimed in claim 1 further including a flush
mechanism coupled to one port of the bottom head manifold.
7. A system as claimed in claim 1 further including a pressure
relief valve coupled to the top head manifold.
8. A system as claimed in claim 1 further including a mechanical
switches coupled between each relay switch and the power module,
and an over temperature sensor coupled to the water heater module
and the mechanical switches for interrupting power supplied to each
relay switch upon sensing a pre-determined temperature of
water.
9. A tankless water heater module comprising: a casing having a
first end, a second end and a plurality of conduits formed therein,
extending from the first end to the second end; a top head manifold
coupled to the first end of the casing and including a port aligned
with each of the plurality of conduits; a bottom head manifold
coupled to the second end of the casing including a port aligned
with each of the plurality of conduits; an immersion heating
element extending through each port of the top head manifold and
into the conduit aligned therewith, each immersion heating element
coupled to the top head manifold; an inlet coupled to one of the
plurality of conduits through the port of the bottom head manifold
aligned therewith; an outlet coupled to another one of the
plurality of conduits through the port of the bottom head manifold
aligned therewith; and a flow path from the inlet to the outlet
through the plurality of conduits, the plurality of conduits
coupled in fluid communication by channels between ports of the top
head manifold and a channel between ports of the bottom head
manifold.
10. A water heater module as claimed in claim 9 wherein each of the
plurality of conduits has two adjacent conduits of the plurality of
conduits.
11. A water heater module as claimed in claim 9 wherein each of the
immersion heating elements is individually removable from the top
head manifold.
12. A water heater module as claimed in claim 9 wherein a pressure
relief valve is coupled to the flow path through one of the top
head manifold and the bottom head manifold.
13. A water heater module as claimed in claim 9 wherein the casing
is generally square in cross section having four quadrants, the
plurality of conduits includes four conduits, one formed in each
quadrant.
14. A water heater module as claimed in claim 13 wherein the top
head manifold includes two channels each coupling two separate ones
of the ports.
15. A water heater module as claimed in claim 14 wherein the bottom
head manifold includes one channel coupling two separate ones of
the ports.
16. A water heater module as claimed in claim 9 further including
an inlet water temperature sensor inserted into the port of the
bottom head manifold to which the inlet is coupled, and an outlet
water temperature sensor inserted into the port of the bottom head
manifold to which the outlet is coupled.
17. A water heater module as claimed in claim 16 further including
a flow sensor carried by the water supply inlet.
18. A water heater module as claimed in claim 16 further including
a flow sensor carried by the bottom head manifold and positioned in
the channel.
19. A water heater module as claimed in claim 9 further including a
flush mechanism coupled to one of the plurality of conduits though
the port of the bottom head manifold aligned therewith other than
the one of the plurality of conduits through the port of the bottom
head manifold aligned therewith coupled to the inlet and the
another one of the plurality of conduits though the port of the
bottom head manifold aligned therewith coupled to the outlet.
20. A water heater module as claimed in claim 9 wherein the heating
elements each include touch safety leads.
21-27. (canceled)
Description
FIELD OF THE INVENTION
[0001] This invention relates to water heaters.
[0002] More particularly, the present invention relates to water
heaters of the type employing resistive heating elements.
BACKGROUND OF THE INVENTION
[0003] The need for heated fluids, and in particular heated water,
has long been recognized. Conventionally, water has been heated by
heating elements, either electrically or with gas burners, while
stored in a tank or reservoir. While effective, energy efficiency
and water conservation can be poor. As an example, water stored in
a hot water tank is maintained at a desired temperature at all
times. Thus, unless the tank is well insulated, heat loss through
radiation can occur, requiring additional input of energy to
maintain the desired temperature. In effect, continual heating of
the stored water is required. Additionally, the tank is often
positioned at a distance from the point of use, such as the hot
water outlet. In order to obtain the desired temperature water,
cooled water in the conduits connecting the point of use (outlet)
and the hot water tank must be purged before the hot water from the
tank reaches the outlet. This can often amount to a substantial
volume of water.
[0004] Many of these problems have been overcome by the use of
tankless water heaters. Heating water accurately and efficiently in
a consistent and safe manner can be problematic with current
tankless systems
[0005] It would be highly advantageous, therefore, to remedy the
foregoing and other deficiencies inherent in the prior art.
[0006] Accordingly, it is an object the present invention to
provide a new and improved tankless water heater.
[0007] Another objective of the present invention is to provide a
modular tankless water heater.
[0008] And another object of the present invention is to provide a
tankless water heater having multiple safety features.
[0009] Yet another object of the present invention is to provide a
tankless water heater which can have flow dynamics adjusted by the
head manifolds.
SUMMARY OF THE INVENTION
[0010] Briefly, to achieve the desired objects of the present
invention in accordance with a preferred embodiment thereof,
provided is a tankless water heater module including a casing
having a first end, a second end and a plurality of conduits formed
therein, extending from the first end to the second end. A top head
manifold is coupled to the first end of the casing and includes a
port aligned with each of the plurality of conduits. A bottom head
manifold is coupled to the second end of the casing and includes a
port aligned with each of the plurality of conduits. An immersion
heating element extends through each port of the top head manifold
and into the conduit aligned therewith. Each immersion heating
element is coupled to the top head manifold. An inlet is coupled to
one of the plurality of conduits through the port of the bottom
head manifold aligned therewith. An outlet is coupled to another
one of the plurality of conduits through the port of the bottom
head manifold aligned therewith. A flow path extends from the inlet
to the outlet through the plurality of conduits, the plurality of
conduits coupled in fluid communication by channels between ports
of the top head manifold and a channel between ports of the bottom
head manifold.
[0011] Also provided is a tankless water heater system having a
power module coupled to a power source, a water heater module, a
relay switch coupled to each immersion heating element and to the
power module, and a control unit receiving fluid flow data and
fluid temperature data from the water heater module. The control
unit is coupled to the relay switches for actuating the relay
switches upon selected fluid flow and fluid temperature data.
[0012] Also provided is a method of heating water including the
steps of providing a tankless water heater module, injecting water
into the flow path, sensing a flow rate of water through the flow
path, sensing temperature of water entering the flow path and
temperature of water exiting the flow path, and supplying power to
selected heating elements determined by the flow rate, the
temperature of water entering the flow path and the temperature of
water exiting the flow path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The foregoing and further and more specific objects and
advantages of the invention will become readily apparent to those
skilled in the art from the following detailed description of a
preferred embodiment thereof, taken in conjunction with the
drawings in which:
[0014] FIG. 1 is a perspective view of the tankless water heater
system according to the present invention;
[0015] FIG. 2 is a perspective view of the tankless water heater
system according to the present invention with the cover
removed;
[0016] FIG. 3 is a perspective view of the housing of the tankless
water heater;
[0017] FIG. 4 is a perspective view of the tankless water heater
module according to the present invention;
[0018] FIG. 5 is a perspective view of the casing of the tankless
water heater module;
[0019] FIG. 6 is a perspective view of the tankless water heater
module of FIG. 4 with the casing removed;
[0020] FIG. 7 is a top perspective view of the tankless water
heater module of FIG. 10;
[0021] FIG. 8 is a bottom perspective view of the tankless water
heater module of FIG. 10;
[0022] FIG. 9 is a bottom perspective view of the top head
manifold;
[0023] FIG. 10 is a top perspective view of the bottom head
manifold;
[0024] FIG. 11 is a top perspective view of the bottom head
manifold of FIG. 14 with sensors installed;
[0025] FIG. 12 is an enlarged sectional side view of the element
coupling assembly;
[0026] FIG. 13 is an exploded view of the element coupling
assembly;
[0027] FIG. 14 is a perspective view of a heating element used in
the tankless water heater module with a portion of the element
coupling assembly;
[0028] FIG. 15 is a perspective view of the heating element of FIG.
14, with a portion of the element coupling assembly exploded
therefrom;
[0029] FIG. 16 is a perspective view of the tankless water heater
module with flush mechanism;
[0030] FIG. 17 is an enlarged partial view of the tankless water
heater system, illustrating sensors used therein;
[0031] FIG. 18 is a perspective view of a pair of water heater
modules coupled in series;
[0032] FIG. 19 is perspective view of the water heater modules of
FIG. 18 with the casings removed; and
[0033] FIG. 20 is a bottom plan view of the water heat heater
modules of FIG. 18.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0034] Turning now to the drawings in which like reference
characters indicate corresponding elements throughout the several
views, attention is directed to FIG. 1 which illustrates a tankless
water heater system generally designated 10. System 10 includes a
housing 12 closed by a cover 11. Tankless water heater system 10 is
a system which heats water as its flows through. Electrical power
is conserved by heating water only as it is needed. As water needs
are increased, increasing amounts of energy are added to the
flowing water to reach a desired temperature.
[0035] Referring to FIGS. 2 and 3, housing 12 acts as a support
structure for the various components of system 10, and includes a
flush aperture 13, an inlet aperture 14 and an outlet aperture 15,
each formed through a bottom sidewall 16. A power inlet 17 is
formed in a top sidewall 18, and a safety valve aperture 19 is
formed in a sidewall 20 extending perpendicularly between bottom
sidewall 16 and top sidewall 18. Housing 12 carries a power module
22, with associated solid-state relay switches 23, a control unit
24, and a water heater module 30. For purposes of this description
and clarity of orientation of the various elements, bottom is a
term which will be used in conjunction with a direction toward
bottom sidewall 16 of housing 12, and top is a term which will be
used in conjunction with a direction toward top sidewall 18 of
housing 12. It will be understood by those skilled in the art that
housing 12 can be oriented to the surrounding environment in
substantially any way, with, for example, bottom sidewall 16
oriented to the side, bottom or top.
[0036] Power module 22 includes a terminal and breaker switch
combination 25 to provide safety and reduce associated elements
needed for installation. No separate or outside breaker box is
necessary for the installation of system 10. Control circuit 24
receives water flow and water temperature data, controlling water
heater module 30 by actuating solid-state relay switches 23. System
10, in the preferred embodiment, also includes mechanical relays
27, which act as safety shut-offs when a predetermined temperature
is equaled or exceeded. These relays are not coupled to controller
24 and are thus independent therefrom. Electrical power runs from
breakers 25 through mechanical relays 27 to solid state relays 23.
When signaled from controller 24, relays 23 provide power to module
30.
[0037] Turning now to FIG. 4, with additional reference to FIG. 5,
water heater module 30 includes a casing 32 which includes a top
end 33, a bottom end 34, and a plurality of conduits 35 extending
therethrough from top end 33 to bottom end 34. In the preferred
embodiment, four conduits 35a, 35b, 35c, and 35d are employed,
although more or less can be used. It has been found that four is
the optimal number, with greater capacity achieved by employing
additional modules, as will be described presently. A top head
manifold 37 is coupled to top end 33 and a bottom head manifold 38
is coupled to bottom end 34. Heating elements 40 extend through top
head manifold 37 into conduits 35. Conduits 35 are sized sufficient
to receive heating elements 40 therein, preferably without contact
between heating elements 40 and the side of the respective conduit
35. In this embodiment, four heating elements 40a, 40b, 40c, and
40d are employed, one for each conduit 35a-d, respectively. As can
be seen, casing 32 is generally square in cross-section, with a
conduit 35 positioned in each quadrant of the square cross-section.
In this configuration, each conduit 35 shares two sides with
adjacent conduits. The result of this orientation is to reduce the
footprint of water heater module 30 and to conserve heat within the
unit. As will become apparent in the ongoing description, heat
radiating from one conduit will radiate into adjacent conduits
thereby reducing heat loss and increasing efficiency. Additionally,
solid-state relay switches 23 are preferably mounted on casing 32
to act as a heat sink. By mounting solid-state relay switches 23 on
casing 32, cold water passing therethrough will collect heat from
the relays increasing their longevity. The heat energy generated by
relay switches 23 will also be conserved by its addition to the
water being heated. As will be understood, relays 23 are preferably
mounted to a side of casing 32 through which the coolest water
passes, such as proximate an inlet thereof. Due to its unique
shape, casing 32 can be constructed in a variety of manners,
including extrusion molding. By employing extrusion molding,
fabrication costs can be greatly reduced.
[0038] Referring to FIG. 9, top head manifold 37, in this
embodiment, has a generally square cross-section adapted to match
top end 33 of casing 32. Top head manifold 37 includes a bottom
surface 42 and a top surface 43. Ports 45a, 45b, 45c, and 45d are
formed through top head manifold 37 extending from bottom surface
42 to top surface 43. Bottom surface 42 abuts top end 33 of casing
32 with ports 45a-d aligning with conduits 35a-d, respectively. A
side port 47 is formed through a side of top head manifold 37 in
communication with port 45c. Bottom surface 42 includes a channel
48 coupling port 45c with port 45d and a channel 49 coupling port
45a with port 45b. The depth and/or width of channel 48 and channel
49 can be increased or decreased depending upon the velocity and
turbulence of fluid flow desired between conduits 35c and 35d and
conduits 35a and 35b. Each port 45a-d has a counter bore formed
from top surface 43, to a point intermediate top surface 43 and
bottom surface 42. The counter bore creates a shoulder 46 within
each port 45a-d. Bypasses 41 extend between ports 45a and 45d, and
between ports 45b and 45c. Bypasses 41 are shallow and are intended
to allow any trapped air or bubbles to equalize between ports 45.
By diffusing between the ports, any build up in one conduit will be
diffused between all, reducing the overall volume taken up by air
in any one conduit.
[0039] With reference to FIG. 10, bottom head manifold 38, in this
embodiment, has a generally square cross-section adapted to match
bottom end 34 of casing 32. Bottom head manifold 38 includes a
bottom surface 52 and a top surface 53. Ports 55a, 55b, 55c, and
55d are formed through bottom head manifold 38 extending from
bottom surface 52 to top surface 53. Caps 56 are employed to close
ports 55b and 55c at bottom surface 52, although port 55c can be
used for a flush mechanism described later. Substantially any
engagement mechanism may be employed to secure caps 46 to ports 55b
and 55c, such as pressure fit, threaded engagement, or the like.
Ports 55b and 55c are preferably formed entirely through bottom
head manifold 38 so as to permit extrusion molding thereof and for
additional features such as the flushing mechanism. However it will
be understood by those skilled in the art that if molding,
machining or other techniques are employed, ports 55b and 55c may
be fabricated with a closed end at bottom surface 52. Top surface
53 abuts bottom end 34 of casing 32 with ports 55a-d aligning with
conduits 35a-d, respectively. Apertures 56a and 56b are formed
through a side of bottom head manifold 38 in communication with
port 55a. Apertures 57a and 57b are formed through a side of bottom
head manifold 38 in communication with port 55d. Top surface 53
includes a channel 58 coupling port 55b with port 55c. The depth
and/or width of channel 58 can be increased or decreased depending
upon the velocity of fluid flow desired between conduit 35b and
conduit 35c. Another sensor aperture 59 can be formed through
channel 58 to bottom surface 52.
[0040] Referring now to FIGS. 6, 7, and 8, water heater module 30
is illustrated without casing 32 to facilitate the description of
the placement of heating elements 40 and the operation of top head
manifold 37 and bottom head manifold 38. Heating elements 40a, 40b,
40c, and 40d are each received through ports 45a, 45b, 45c, and
45d, respectively, of top head manifold 37, extend through conduit
35a, 35b, 35c, and 35d, respectively, of casing 32 and terminate
proximate port 55a, 55b, 55c, and 55d, respectively, of bottom head
manifold 38. Heating elements 40 can be secured in position with
caps of each received within ports 45 of top head manifold 37.
Ports 45 can be threaded to threadably receive and securely hold
the caps with matching threads. The caps would be threaded into
ports 45 to effectively seal ports 45 and to permit quick and easy
removal thereof. While this is a likely removable engagement
mechanisms, the preferred method of attachment is illustrated in
FIGS. 12, 13, 14, and 15, as will be described presently. The
purpose for providing an easily disengageable engagement between
heating elements 40 and ports 45 is to permit quick and easy
exchange of heating elements 40. Heating elements 40 can have
greater or lesser heating capability. Thus, if higher temperatures,
greater flow rates or just larger volumes of water are desired,
higher output heating elements 40 can replace lower output elements
in water heater modules 30. As an example, a water heater system 10
having a single module 30 is installed at a location. Over time,
larger volumes of water are used, increasing the flow rate of water
through water heater module 30 and maxing out its performance.
Instead of having to replace the entire module to upgrade the
performance, the lower capacity heating elements are replaced with
greater capacity elements. At some point, if performance needs to
increase past the level of replacing heating elements, additional
water heater modules can be installed to expand the system, as will
be described presently.
[0041] With reference to FIGS. 14 and 15, each heating element 40
is an elongated immersion resistive heating element 62 terminating
in leads 63. In this embodiment an element coupling assembly 70
couples each heating element 40 to top head manifold 37 and
provides safe connection between power module 22 and heating
elements 40. Element coupling assembly 70 includes a cap assembly
72 carried by leads 63 of each heating element 40, and for purposes
of this disclosure, is considered a part thereof. Cap assembly 72
includes an O-ring 73, a seal housing 74 holding seals 75, and a
compression cap 78. Leads 63 are received through O-rings 73
carried by seal housing 74 and into apertures 79 formed through
compression cap 78.
[0042] With additional reference to FIGS. 12 and 13, heating
elements 40 are inserted through top head manifold 37, into casing
32. Element coupling assembly 70 is employed to securely retain
each heating element 40, providing touch safety and coupling each
heating element 40 to top head manifold 37. For purposes of this
disclosure, touch safety leads includes a flying lead as described
previously wherein the leads are potted into a cap of the heating
elements, a modified flying lead such as provided by cap assembly
72, and the like. Coupling assembly 70 includes cap assemblies 72
associated with each heater element 40, and a keeper plate 80. When
each heater element 40a-d and associated cap assembly 72 is
positioned through top head manifold 37 such that each cap assembly
abuts shoulder 46 of the respective port 45, keeper plate 80 is
positioned. Keeper plate 80 includes an opening 82 for each
compression cap 78. Compression caps 78 include an enlarged base 83
having a diameter greater than openings 82. When keeper plate 80 is
securely bolted to top header manifold 37, and tightened down, each
compression cap compresses O-rings 73, seal housings 74 and seals
75 against shoulders 46, sealing heating elements 40 in position
and preventing leaks from module 30. Coupling assembly permits
removal of any or all heating elements 40a-d by removing keeper
plate 80. Additionally, cap assemblies 72 prevent accidental or
inadvertent contact with leads 63, providing added safety.
[0043] Referring back to FIGS. 6, 7, and 8, a water supply inlet 90
is coupled to port 55a of bottom head manifold 38. A hot water
supply outlet 92 is coupled to port 55d of bottom head manifold 38.
Water flow through conduits 35 is facilitated by top head manifold
37 and bottom head manifold 38. Water enters water heater module 30
from water supply inlet 90 through port 55a of bottom head manifold
38 into conduit 35a. Water flows from conduit 35a through port 45a,
channel 49, and port 45b of top head manifold 37 into conduit 35b.
Water flow continues from conduit 35b through port 55b, channel 58,
and port 55c of bottom head manifold 38 into conduit 35c. Finally,
in this four conduit embodiment, water flows from conduit 35c
through port 45c, channel 48, and port 45d of top head manifold 37
into conduit 35d. From conduit 35d, the water exits water heater
module 30 through port 55d and into hot water supply outlet 92 to
be used as desired. In this manner, the temperature of the water
can be adjusted relative the flow rate by the number of heating
elements 40 powered and to the extent they are powered.
[0044] A substantial advantage provided by top head manifold 37 and
bottom head manifold 38 is the high degree of control provided over
the water flowing through module 30. Specifically, channels 48 and
49 of top head manifold 37 and channel 58 of bottom head manifold
38 can be configured to alter flow characteristics through each
conduit 35d, 35b, and 35c, respectively. Flow characteristics
include velocity, direction and turbulence generated. These are
altered by the volume of each channel (width and depth), and the
shape or direction. By increasing the velocity, or directing the
flow against another object, for example, turbulence can be
created. Turbulence in water flow through a conduit can prevent or
reduce surface boiling and stir up any particulate matter,
preventing deposits and build-up. The channels permit a high degree
of flexibility in module 30 to allow the flow characteristics to be
altered as desired.
[0045] As can be understood from the description and seen from the
drawings, top head manifold 37 and bottom head manifold 38 permit
conduits 35 to share much of the thermal energy generated by
heating elements 40 instead of radiating the energy to the
surrounding environment. Additionally, while a distinct flow path
sequentially through conduits 35 having heating elements 40 is
provided, top head manifold 37 and bottom head manifold 38
cooperate to form a single container with respect to pressure water
heater module 30. Due to this unique characteristic, a pressure
relief valve 95 can be employed for increased safety. Pressure
relief valve 95 is coupled to side port 47 of top head manifold
37.
[0046] As briefly mentioned previously, a flush mechanism 100 can
be added to the system if desired as shown in FIG. 16. Flush
mechanism 100 can be attached to either of the remaining ports 55b
or 55c of bottom head manifold 38. In the embodiment illustrated,
cap 46 is removed from port 55c and a flush conduit 102 is
connected thereto. A valve 104 is coupled to conduit 102 permitting
opening and closing thereof to flush water from tankless water
heater system 10, and module 30 specifically. Valve 104 can be
manually operated or include a solenoid or similar device for
automatic operation. Flush conduit 102 can tie into a disposal or
drain pipe as available, and can be coupled to a conduit 106
extending from pressure relief valve 95.
[0047] With reference to FIGS. 11 and 17, data is provided to
control unit 24, by a flow sensor 110 carried by water supply inlet
90. In this embodiment, flow sensor 110 is a paddle wheel pulse
flow sensor which allows the volume of water entering water heater
module 30 to be measured. Inlet water temperature is sensed by
inlet temperature sensor 112 inserted into port 55a through
aperture 56a. Outlet water temperature is sensed by outlet
temperature sensor 114 inserted into port 55d through aperture 57a.
Temperature sensors 112 and 114 allow the temperature of water
entering and exiting water heater module 30 to be measured. This
data is employed by control unit 24 to activate one or more heating
elements 40, and adjust the power to each element activated through
solid state relay switches 23. Various methodologies can be
employed to control and adjust the operation of the heating
element. This is typically controlled by software within control
unit 24. An over temperature sensor 115 is inserted into port 55d
through aperture 57b. Over temperature sensor 115 senses outlet
water temperatures exceeding a specific temperature. When
temperatures equal to or exceeding the predetermined temperature
are detected, over temperature sensor 115 cuts power to mechanical
relays 27, preventing power from reaching relays 23. This circuit
is a safety which bypasses controller 24 and shuts down heating
elements 40 even if controller 24 signals relays 23 to apply power.
A grounding lug 118 is inserted into port 55a through aperture 56b.
Grounding lug 118 permits grounding of the electronic components
with module 30.
[0048] Still referring to FIGS. 11 and 17, a flow sensor 120 can be
added as an addition to or replacement for flow sensor 110. In some
instances, the velocity of inflowing water can be at a low level
that is difficult to accurately sense. If this is the case, for
example, due to large volumes resulting in low velocities, a ribbon
flow sensor can be inserted into channel 58 of bottom head manifold
38 through aperture 59. If flow velocities are low enough to cause
a detection problem, channel 58 can be narrowed to increase the
velocity of the flow therethrough to level which can be accurately
measured. Various types of flow sensors can be utilized in this
application.
[0049] As briefly touched upon previously, tankless water heater
system 10 can be expanded to increase its capacity by include
multiple water heater modules 30. Referring to FIGS. 18, 19, and
20, a pair of water heater modules 30 are coupled in series. It
will be understood that modules 30 can be coupled In parallel or in
series using reverse return techniques. As can be seen, each is
identical and therefore interchangeable to provide a modular,
expandable system. For purposes of this description, reference
numerals will be modified with a prime for the additional module.
Water heater module 30 is generally identical to that described
previously in FIG. 4 with water inlet 90 coupled to water outlet
92' of water heater module 30'. Water heater 30' is substantially
identical to water heater module 30. A water supply inlet 90' is
coupled to water heater module 30'. Thus, water enters water heater
module 30' through port 55a', flows through the conduits as
previously described and exits water heater module 30' through port
55d'. Water exiting water heater module 30' enters into coupling
conduit 130 coupling water outlet 92' to water inlet 90. Water
flows through the conduits as previously described and exits water
heater module 30 through port 55d. Adding additional modules
expands the capacity of system 10 to heat water. An expandable
system can include housing 12 having the capacity to receive one or
more additional water heater modules 30 with the ability to add
corresponding terminal and breaker switch combinations 25.
[0050] Various changes and modifications to the embodiments herein
chosen for purposes of illustration will readily occur to those
skilled in the art. To the extent that such modifications and
variations do not depart from the spirit of the invention, they are
intended to be included within the scope thereof, which is assessed
only by a fair interpretation of the following claims.
[0051] Having fully described the invention in such clear and
concise terms as to enable those skilled in the art to understand
and practice the same, the invention claimed is:
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