U.S. patent application number 11/554899 was filed with the patent office on 2008-05-01 for thermal analysis of apparatus having multiple thermal control zones.
This patent application is currently assigned to HUSKY INJECTION MOLDING SYSTEMS LTD.. Invention is credited to Zakiul HAQUE, James Osborne PLUMPTON.
Application Number | 20080099569 11/554899 |
Document ID | / |
Family ID | 39328935 |
Filed Date | 2008-05-01 |
United States Patent
Application |
20080099569 |
Kind Code |
A1 |
PLUMPTON; James Osborne ; et
al. |
May 1, 2008 |
Thermal Analysis of Apparatus having Multiple Thermal Control
Zones
Abstract
Systems and methods for conducting thermal analysis in materials
and devices having multiple thermal control zones are provided.
Modem apparatuses, such as manifolds, generally have several
thermal devices that introduce or remove heat at different rates
from several different regions. Previous attempts to determine a
thermal profile required constant guessing and an unknown number of
simulations to arrive at an acceptable result. Further, since the
number of simulations required is not known from the onset of the
operation, the duration is unknown, which is often unsatisfactory
to manufacturing personnel. Disclosed embodiments include the use
of FEA to aid in designing and/or evaluating manifold systems. In
one embodiment, finite element analysis is conducted to determine
the heat flux caused upon other control zone by a thermal device in
a specified control zone.
Inventors: |
PLUMPTON; James Osborne;
(Enosburg Falls, VT) ; HAQUE; Zakiul; (Essex,
VT) |
Correspondence
Address: |
HUSKY INJECTION MOLDING SYSTEMS, LTD;CO/AMC INTELLECTUAL PROPERTY GRP
500 QUEEN ST. SOUTH
BOLTON
ON
L7E 5S5
US
|
Assignee: |
HUSKY INJECTION MOLDING SYSTEMS
LTD.
Bolton
CA
|
Family ID: |
39328935 |
Appl. No.: |
11/554899 |
Filed: |
October 31, 2006 |
Current U.S.
Class: |
236/1B |
Current CPC
Class: |
B29C 2945/7628 20130101;
B29C 45/78 20130101; B29C 45/7693 20130101; B29C 2945/7604
20130101; B29C 45/2725 20130101; B29C 33/3835 20130101 |
Class at
Publication: |
236/1.B |
International
Class: |
F24D 19/10 20060101
F24D019/10 |
Claims
1. A method of determining a thermal parameter of an apparatus, the
method comprising: (a) providing a model of an apparatus having a
plurality of thermal control zones, each thermal control zone of
the apparatus comprising a thermal controller and a thermal device,
wherein the thermal controller of each thermal control zone is
operative, in response to a thermal parameter at a location within
that thermal control zone, to generate a control signal directly or
indirectly to the thermal device of that thermal control zone; (b)
providing at least one input value that directly or indirectly
corresponds to at least one thermal property of at least one
material of the apparatus; (c) defining a finite element analysis
mesh having nodes for the model of the apparatus; (d) applying at
least one boundary condition value to at least one portion of the
model of the apparatus; (e) determining the thermal correlation
among at least a selected plurality of the thermal control zones,
comprising constructing an [n.times.n] influence matrix of matrix
values, where n equals the number of selected thermal control
zones, each matrix value corresponding to a value of a first
thermal parameter selected from heat loss and temperature for a
corresponding one of the thermal control zones, the constructing of
the [n.times.n] influence matrix comprising conducting n finite
element analysis simulations of the apparatus based on the finite
element analysis mesh, the input value of (b) and the boundary
condition value, each of the n finite element analysis simulations
comprising determining a matrix value of the first thermal
parameter for each thermal control zone by applying a value for the
other thermal parameter selected from heat loss and temperature
which is unknown to each boundary of a corresponding one of the
thermal control zones; and (f) using the finite element analysis
influence matrix to determine the value of the second thermal
parameter for each control zone for a desired value of the first of
the first thermal parameter for each control zone included in the
selected plurality of thermal control zones.
2. The method of claim 1, further comprising: (g) applying the
result obtained in (f) to a finite element analysis simulation the
model of (a) to obtain a thermal parameter for the apparatus.
3. The method of claim 1, further comprising: (g) applying the
result obtained in (f) to an finite element analysis simulation the
model of (a) to obtain a thermal profile for the apparatus.
4. The method of claim 3, further comprising: (h) utilizing the
thermal profile of (g) to evaluate a malfunction in an existing
apparatus.
5. The method of claim 1, wherein the thermal device is selected
from the group consisting of: a heater, thermoelectric cooler, heat
sink, heat pipe, and combinations thereof.
6. The method of claim 1, wherein the apparatus is a manifold
configured to transport a material that is a fluid.
7. The method of claim 6, wherein the manifold comprises a
plurality of components and wherein at least a portion of the
plurality of components comprise one control zone.
8. The method of claim 1, wherein Equation (1) is utilized in
association with the influence matrix to obtain a linear thermal
relationship, wherein the unknown thermal parameter for each
thermal control zone is the heat flux and the known first thermal
parameter is a temperature value at the thermal controller for each
thermal control zone, thereby determining how much heat needs to
come from a thermal device in a specific thermal control zone to
get a certain temperature at the thermal controller in the same
thermal control zone.
9. The method of claim 1, wherein the input value of (b) further
corresponds to a thermal property of a node of the mesh defined in
(c).
10. The method of claim 1, wherein the input value of (b) further
corresponds to a thermal property of a thermal control zone of the
apparatus.
11. A method comprising: (a) receiving a model of an apparatus
having a plurality of thermal control zones, each thermal control
zone of the apparatus comprising a thermal device controlled by a
thermal controller, wherein each thermal controller is configured
to transmit, in response to a thermal parameter at a specific
location within the apparatus, a control signal to the thermal
device; (b) providing at least one input value that directly or
indirectly corresponds to at least one thermal property of at least
one material of the apparatus; (c) defining a finite element
analysis mesh having nodes for the model of the apparatus; (d)
applying at least one boundary condition value to at least one
portion of the model of the apparatus (e) determining the thermal
correlation among at least a selected plurality of the thermal
control zones, comprising constructing an [n.times.n] influence
matrix of matrix values, where n equals the number of selected
thermal control zones, by applying a known thermal parameter for
each control zone within the influence matrix and conducting n
simulations, wherein the constructing of the [n.times.n] influence
matrix comprising conducting n finite element analysis simulations
of the apparatus based on at least the finite element analysis mesh
and the input value of (b) and the boundary condition value; and
(f) using the influence matrix to obtain a result of the linear
thermal relationship of an unknown thermal parameter for each
control zone within the influence matrix
12. The method of claim 11, wherein the thermal controller is
within the same thermal control zone as the thermal device it is
controlling.
13. The method of claim 11, further comprising: (g) receiving at
least one user input that modifies the mesh defined in (c).
14. The method of claim 11, further comprising: (g) applying the
result obtained in (f) to the model of (a) to obtain a thermal
profile for the apparatus.
15. The method of claim 14, further comprising: (h) utilizing the
result obtained in (g) to evaluate a malfunction in an existing
apparatus.
16. The method of claim 14, further comprising: (h) utilizing the
result obtained in (g) in designing a physical apparatus of the
model received in (a).
17. The method of claim 11, wherein the known thermal parameter for
each thermal control zone comprises the temperature at the thermal
controller.
18. The method of claim 11, wherein the known thermal parameter for
each thermal control zone comprises the heat loss across a boundary
of the control zone.
19. The method of claim 11, wherein Equation (1) is utilized in
association with the influence matrix to obtain the linear thermal
relationship, wherein the unknown thermal parameter for each
control zone is the heat flux and the known thermal parameter is a
temperature value at the thermal controller for each thermal
control zone, thereby determining how much heat needs to come from
a heater in a specific thermal control zone to get a certain
temperature at the thermal controller in the same thermal control
zone.
20. The method of claim 11, wherein the apparatus is a manifold
having a plurality of channels configured to transport a fluid.
21. The method of claim 11, wherein the input value of (b) further
corresponds to a thermal property of a node of the mesh defined in
(c).
22. A system comprising: a computing device having a
computer-readable medium configured to receive computer-executable
instructions that when executed provide a model of an apparatus
having a plurality of thermal control zones, each thermal control
zone of the apparatus comprising a thermal device controlled by a
thermal controller, wherein each thermal controller is configured
to transmit, in response to a thermal parameter at a specific
location within the apparatus, a control signal to the thermal
device; an input device operatively coupled to the computing device
configured to allow the reception of at least one input regarding
at least one material of the apparatus and an input relating to at
least one boundary condition; a computer-readable medium having
computer-readable instructions for defining a mesh having nodes for
the model of the apparatus; and a computer-readable medium having
computer-readable instructions that when executed construct an
[n.times.n] influence matrix, where n equals the number of selected
thermal control zones, each matrix value corresponding to a value
of a first thermal parameter selected from heat loss and
temperature for a corresponding one of the thermal control zones,
the constructing of the [n.times.n] influence matrix comprising
conducting n finite element analysis simulations of the apparatus
based on the finite element analysis mesh, the input value of (b)
and the boundary condition value, each of the n finite element
analysis simulations comprising determining a matrix value of the
first thermal parameter for each thermal control zone by applying a
value for the other thermal parameter selected from heat loss and
temperature which is unknown-to each boundary of a corresponding
one of the thermal control zones and using the finite element
analysis influence matrix to determine the value of the second
thermal parameter for each control zone for a desired value of the
first of the first thermal parameter for each control zone included
in the selected plurality of thermal control zones.
23. The system of claim 22, further comprising: a computer-readable
medium having computer-readable instructions that when executed
apply the result of the linear thermal relationship to the model to
obtain a thermal profile for the apparatus.
24. The system of claim 23, further comprising: a display adapter
operatively coupled to the computing device for displaying the
thermal profile of the apparatus.
25. The system of claim 23, further comprising: a computer-readable
medium having computer-readable instructions that when executed
analyze the thermal profile of the apparatus to evaluate any
malfunctions of a physical apparatus having characteristics that
are similar to the model.
26. The method of claim 25, wherein the apparatus is a manifold
having a plurality of channels configured to transport a fluid.
27. The method of claim 26, wherein the apparatus is a manifold
having a plurality of channels configured to transport a material
that is a fluid at an elevated temperature and a solid at a lowered
temperature.
28. The system of claim 23, further comprising: a computer-readable
medium having computer-readable instructions that when executed
utilize the thermal profile of the apparatus in designing a
physical apparatus having characteristics that are similar to the
model.
29. The system of claim 23, wherein the known thermal parameter for
each thermal control zone comprises the temperature at the thermal
controller.
30. The method of claim 23, wherein the computer-readable medium
having computer-readable instructions that when executed construct
an [n.times.n] influence matrix comprises instructions for
performing Equation (1) in association with the influence matrix to
obtain a linear thermal relationship, wherein the unknown thermal
parameter for each thermal control zone is the heat flux and the
known first thermal parameter is a temperature value at the thermal
controller for each thermal control zone, thereby determining how
much heat needs to come from a thermal device in a specific thermal
control zone to get a certain temperature at the thermal controller
in the same thermal control zone.
Description
INTRODUCTION
[0001] This invention relates to systems, methods and devices for
conducting thermal determinations of apparatus, such as design or
analysis of apparatus or devices. More specifically, aspects of the
invention are directed towards thermal design or analysis of
apparatus or devices having multiple thermal control zones.
BACKGROUND
[0002] Industrial tools and other apparatus are often placed under
high stress loads. The stress may be in the form of, for example,
mechanical, frictional, and/or extreme thermal conditions. This is
especially true of tools utilized in manufacturing products under
high temperatures and pressures, such as tools for making injection
molded plastic products. Such tools must not only be designed to
withstand the thermal conditions, but also to remain within certain
pre-defined operating thermal parameters for proper operation. For
example, when injection molding resin or other materials to create
plastic products, utilizing a temperature that is too high could
result in "burning" the resin and/or improper formation of the
desired product. Conversely, if a desired temperature is not
reached, the resins may not properly flow or mix or otherwise
perform suitably to form the desired end-product. The complex
problem of properly designing apparatus such as industrial tools is
compounded when the apparatus has multiple thermal zones, each
comprising one or more thermal devices, such as heaters or coolers,
that affect temperature in their own zone and that of other zones
of the apparatus.
[0003] Modern apparatus, for example injection molding manifolds
and the like, generally have more than one thermal device, each of
which, as explained in more detail below, introduces or removes
heat from the apparatus. Generally, each region or zone of the
apparatus is in thermal communication with one or more other zones
of the apparatus. Thus designing and analyzing the thermal
properties or performance of such apparatus, including, for
example, determining a thermal profile of the apparatus under usage
conditions, requires recognition that each zone impacts the thermal
properties or performance of one or more other zones. As one
skilled in the art will readily appreciate, this is a complex and
time consuming undertaking, especially with an apparatus having
multiple thermal control zones, where each zone has a control
associated with a thermal device whose thermal output affects the
thermal properties or performance of one or more of the other
control zones, each of which may, in turn, have a control and an
associated thermal device that influences the thermal properties or
performance of the first and/or other control zones of the
apparatus.
[0004] Previous approaches used to determine a thermal profile of
an apparatus included the use of an iterative process employing
finite element analysis (FEA). Typically, in such prior approaches,
a large number of calculation simulations are needed to approach an
estimation of the thermal profile of the apparatus in operation.
Such simulations require undesirably large amounts of computing and
personnel time. Also unfortunately, such known iterative processes
require guessing or estimating the value of one or more variables
and an unknown number of simulations to arrive at an acceptably
accurate result. The required computational time for each
successive simulation to be performed often precludes the
computation of a fully satisfactory estimate of the thermal profile
of the apparatus. Rather the process is often stopped or otherwise
not conducted before a more precise and accurate result is
obtained. Further, since the number of simulations required is not
known from the onset of the operation, the duration is unknown,
which is often unsatisfactory to manufacturing personnel. Where
each of multiple zones of an apparatus has a thermal device whose
thermal output indirectly affects the thermal properties of one or
more of the other control zones, the synergistic complexity of the
problem increases as the number of control zones increases.
[0005] Some or all of these and other shortcomings of traditional
methods of determining a thermal profile of an apparatus having a
plurality of thermal control zones are overcome according to
various methods and systems encompassed in different embodiments of
the invention. Additional objects or advantages of various
embodiments of the invention will be apparent from the following
disclosure.
SUMMARY
[0006] A first aspect of the invention is directed towards methods
and systems implementing finite element analysis to aid in the
determination, e.g., the design or analysis, of an apparatus having
multiple thermal control zones. In certain exemplary embodiments
the methods and systems are fixed-simulation methods and systems,
as further disclosed below. In certain exemplary embodiments, the
apparatus has multiple thermal control zones, each of which control
zones has a control (also referred to here as a thermal controller)
and an associated thermal device, such as a heater or cooler, whose
thermal output directly affects the thermal performance or
properties (e.g., the temperature) of that zone and also directly
or indirectly affects the thermal properties of one or more of the
other control zones of the apparatus. In certain exemplary
embodiments, the apparatus to be designed or analyzed is a manifold
for injection molding plastic or other material, wherein the
manifold has multiple thermal control zones, each of which control
zones has a control and an associated thermal device whose thermal
output directly affects the temperature of that zone and indirectly
affects the temperature of one or more of the other control zones
of the manifold.
[0007] It will be understood by those skilled in the art, given the
benefit of this disclosure, that the thermal device of any such
zone of the apparatus may comprise operative components at one or
more locations in the zone. In addition, the boundary between one
thermal control zone and the next within an apparatus may in some
instances be selected from amongst multiple (even infinite)
suitable alternatives. As one skilled in the art will readily
appreciate upon reading the disclosure herein, the term boundary
does not signify a physical separation or boarder (although in
select embodiments, the boundary will be defined by a physical
structure). Rather, the boundary may be virtual and defined merely
on non-physical features. In select embodiments, the apparatus is
divided up into several symmetric portions. As used herein, the
boundaries between control zones may be any line, collection of
lines, plane or collection of planes defining at least a portion of
border of a specific control zone.
[0008] Typically, but not necessarily in all embodiments disclosed
here, a thermal zone of a multi-zone apparatus designed or analyzed
by a finite element analysis method or system disclosed here is not
controlled by the thermal controller of another zone other than
indirectly, such as by the cross-boundary effect of the temperature
of one zone on adjoining zones. It will be within the ability of
those skilled in the art, given the benefit of this disclosure, to
determine suitable zone boundaries.
[0009] In accordance with another aspect, certain systems and
methods disclosed here employ a finite element analysis to
determine, i.e., to design or to analyze the design of apparatus
(i.e., within all or at least a portion of the body of the
apparatus or of components of the apparatus) having multiple,
independently controlled thermal control zones, wherein the
temperature of at least one such zone during operation of the
apparatus directly or indirectly affects the temperature of at
least one other such zone. As the term is used here, zones are
"independently controlled" if (i) the thermal device(s) within the
zone are actuated (e.g., operated or energized) only in response
(directly or indirectly) to signals generated by one or more
temperature sensors within that zone and/or (ii) the thermal
device(s) within the zone are not adapted to be actuated in
response (directly or indirectly) to signals generated by any
temperature sensor(s) within any other zone of the zone.
[0010] In certain exemplary embodiments finite element analysis is
implemented to aid in the design or analysis of a manifold system,
e.g., an injection molding manifold system, comprising one or more
than one individual manifold. In certain embodiments, for example,
fixed-simulation finite element analysis is conducted to determine
the heat flux caused by actuation of a thermal device in a
specified control zone of the manifold system upon one or more
other control zones of the manifold system. In certain such
embodiments, the thermal device of a control zone is a heater, such
as but not limited to resistive heater. In certain exemplary
embodiments the heater is operative to heat a liquid or other fluid
in a channel extending in the manifold, including at least
partially in the particular control zone in question. Yet in other
embodiments, the heater is operative to maintain an elevated
temperature of a liquid or other fluid in the manifold. As used
herein, the term liquid may include any chemical, matter or
material that may change shape as it travels through a passage,
such as a channel. For example, the liquid may be fine or course,
and at select temperatures be considered a semi-solid. The texture
of the liquid may range from dense to soft and from runny to a
paste-like consistency including slurries. Thus, in select
embodiments, the liquid forms to the shape of the passage it is
traveling within.
[0011] In certain exemplary embodiments the thermal device of a
control zone is a cooler or chiller, e.g., a thermoelectric cooling
device operative to remove heat from the zone in question. Other
embodiments of the invention will be readily apparent to those of
ordinary skill in the art, including, e.g., embodiments wherein
finite element thermal analysis as disclosed here is used to
determine other thermal parameters. As used here, the term thermal
parameters is used to mean the thermal operating properties,
thermal performance under normal operating conditions or under
other conditions, thermal profile (temperature gradients or the
like) and/or other properties, characteristics, etc. of an
injection molding manifold or other apparatus having multiple
thermal control zones.
[0012] In accordance with another aspect, systems and methods
comprise implementation of finite element thermal analysis to
determine the thermal parameters of an apparatus having multiple
control zones, and further comprises utilizing the results of such
analysis, e.g., the thermal relationship between zones of the
apparatus obtained from such finite element analysis to determine a
thermal profile of the apparatus under defined conditions. In
certain exemplary embodiments, the thermal profile graphically
displays the temperature values obtained, e.g., by one or more
graphical displays visible to a user. In further embodiments, the
thermal profile may be utilized to further aid in the design of the
apparatus, e.g., determining an initial design for the apparatus
before it is constructed or determining an alteration of the
existing design of the apparatus.
[0013] In accordance with another aspect of the invention, finite
element analysis is utilized in a system or method to create an
influence matrix suitable for use in determining the design of an
apparatus, e.g., to aid in the confirmation of a thermal profile of
an injection molding manifold or other apparatus having multiple
control zones. In certain exemplary embodiments, one control zone
may span over multiple components.
[0014] In certain exemplary embodiments finite element thermal
analysis is employed to determine the thermal profile of a
defectively operating apparatus having multiple control zones,
e.g., an injection molding manifold, and the thermal profile is
used in determining why the apparatus is operating defectively,
e.g., not operating optimally or effectively or according to
expectations or specifications or otherwise malfunctioning. In
certain such embodiments, the results of such determination are
utilized to determine a design change or other steps to correct the
deficiency. One skilled in the art will readily appreciate that one
or more of the steps or features of the methods and systems
disclosed here may be carried out by computer-executable
instructions stored on one or more computer-readable mediums.
[0015] Those of ordinary skill in the art will recognize and
understand from this disclosure and the further discussion below,
various alternative and optional additional features and advantages
of the methods and systems disclosed here for implementing finite
element analysis in the design or analysis of apparatus having
multiple thermal control zones. Also, additional aspects and
advantages of the present invention will be apparent to those
skilled in the art from the following detailed description of
certain embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The following detailed discussion of certain select
embodiments will refer to the appended drawings in which:
[0017] FIG. 1 is a flowchart of an exemplary finite element
analysis method or system according to one aspect of the invention,
for determining the thermal profile of an apparatus having multiple
thermal control zones.
[0018] FIG. 2a shows a perspective view of an exemplary model of a
multi-component injection molding manifold having multiple thermal
control zones, which may be analyzed by a finite element analysis
method or system according to certain exemplary embodiments of the
invention.
[0019] FIG. 2b is a perspective view of an exemplary modeled
portion of a manifold having multiple thermal control zones, which
may be analyzed by a finite element analysis method or system
according to certain exemplary embodiments of the invention.
[0020] FIG. 3a is an exemplary thermal matrix providing exemplary
data to illustrate a finite element analysis method or system
according to certain exemplary embodiments of the invention.
[0021] FIG. 3b is an exemplary temperature matrix of a manifold
having three control zones, providing exemplary data to illustrate
a finite element analysis method or system according to certain
exemplary embodiments of the invention.
[0022] FIG. 4 is a perspective view of an exemplary thermal profile
of a portion of a manifold system having more than one control
zone, utilizing the data shown in FIG. 3b.
DETAILED DESCRIPTON OF CERTAIN EXEMPLARY EMBODIMENTS
[0023] The exemplary methods and systems herein are further
disclosed and described below in the context of industrial
injection molding manifolds for ease of understanding only,
however, one skilled in the art will readily understand that other
applications, industrial or otherwise, are within the scope of the
invention. Thus, the finite element methods and systems of the
present disclosure are useful in analyzing or designing any
apparatus having multiple thermal control zones. As used here, the
term apparatus is used broadly to mean apparatus, devices,
assemblies, sub-assemblies and the like.
[0024] FIG. 1 is an exemplary flowchart of a method of analyzing
the design of a manifold according to one aspect of the invention.
The applicability of FIG. 1 and the description below to system
embodiments of the present invention will be readily apparent to
those of ordinary skill in the art given the benefit of this
disclosure. As one skilled in the art will readily appreciate, the
method may be modified to include fewer or additional steps
according to various embodiments of the invention. The method of
FIG. 1 can be utilized to determine the design of a manifold, e.g.,
to develop a suitable design for a manifold. Further, the method
may be utilized to analyze the design of an existing manifold,
e.g., to develop a thermal profile comprising estimated temperature
gradients within the manifold under a defined set of conditions,
e.g. under the manifold's normal operating conditions. The method
may also be modified according to the teachings of this disclosure
to redesign an existing manifold. This would be particularly
advantageous when an existing manifold is not operating properly or
efficiently. For example, scorching or improper flow of injection
molding material may be due to temperatures in one or more of the
zones of the manifold (at some or all times during the injection
molding cycle) which are too high or too low. Adjusting the thermal
controller for that zone may or may not be suitable or sufficient
to correct the problem. For example, adjusting the thermal
controller for that zone may not be suitable or sufficient if it is
being adversely affected by the thermal properties (e.g., the
temperature) of one or more of the other control zones. One or more
methods as disclosed and described here may be utilized to
determine the source of the problem, provide a result to suggest a
particular retrofit or adjustment to remedy the problem, and/or aid
in the design of such a retrofit. Such adjustment may, for example,
be in the design of the manifold and/or in the manner in which it
is operated, including, e.g., the temperature set points of the
zone controllers, etc.
[0025] At exemplary step 102 of FIG. 1, a model of an apparatus,
such as a manifold system, having a plurality of thermal control
zones is received. As used herein, each thermal control zone of the
manifold has at least one thermal input and at least one thermal
output. According to one embodiment of the invention, each thermal
control zone comprises a thermal controller and a thermal device.
The thermal controller typically is configured to transmit a
control signal (or not transmit such a signal), in response to a
thermal parameter at a specific location within the manifold, e.g.,
a thermocouple or other temperature sensor adapted to transmit or
not transmit a signal in response to the temperature of the
manifold at the location of the sensor in the zone in question
being below or above a set point. The signal may be transmitted by
the sensor directly to the thermal device, i.e., to the thermal
device or to an associated microprocessor or the like or other
circuitry to cause ultimately a corresponding actuation or
de-actuation of the thermal device. It should be understood in this
regard that, while a single microprocessor or the like or other
circuitry may be used to receive and process control signals from
the sensors or other controllers of multiple zones, the control
signal from the thermal controller of a particular zone is the sole
or primary control signal for the thermal device(s) of that
particular control zone. As used herein, a thermal device for a
zone may be any device operative under the control of the
associated controller to heat or cool the zone, for example, an
electric, fluidic or other heater, thermoelectric cooler, heat
sink, heat pipe, or any combination thereof. In essence any
component or group of components that is intentionally configured
to provide or remove thermal energy from the control zone may be a
thermal device.
[0026] As used herein, an apparatus or system may comprise one or
more components that are in thermal communication with each other.
FIG. 2a shows an exemplary model of multi-component manifold that
may be employed according to one implementation of step 102 of FIG.
1. Manifold system 200 includes manifold 202 and manifold 204
which, in turn, can be conceptually divided into multiple thermal
control zones for analysis in accordance with the methods and
systems disclosed here. Each of the multiple thermal control zones
has a thermal controller and an associated thermal device. As
shown, manifold 202 includes thermal device 206 and thermal
controller 208.
[0027] The model of manifold system 200 may be configured such that
thermal controller 208 detects, measures, receives or otherwise
determines a thermal parameter of or corresponding to its thermal
zone, such as the temperature of the manifold at thermal controller
208 or the temperature of resin or other molding material fed
through channel 210 of the manifold to molding cavities. In certain
other exemplary embodiments, multiple thermal controllers may be
utilized in a thermal control zone to detect, measure, receive or
otherwise determine the thermal parameter(s) at multiple locations
within the zone. The control signals from such multiple controllers
may be used collectively (e.g., with averaging or other combination
or selective elimination, etc.), serially, or otherwise to control
the heater or other thermal device of the zone.
[0028] Other thermal parameters, i.e., other determinable values or
parameters corresponding to the temperature or other suitable
thermal property of the zone, may be utilized, such as but not
limited to conduction, convection, radiation, and/or internal heat
generation. In response to the thermal parameter at a specific
location within the apparatus, thermal controller 208 is configured
to transmit a control signal directly or indirectly to thermal
device 206 located within the same control zone as thermal
controller 208. As noted above, the control signal may be fed
directly to the thermal controller or may utilize an indirect
connection, such as via a microprocessor or the like. As will be
appreciated by those skilled in the art, such a process may be
partly or wholly implemented through the use of computer-executable
instructions stored on one or more computer-readable mediums that
are in electronic communication with one or more such
processors.
[0029] Thermal device 206 and any associated circuitry, devices or
the like, including, e.g., electrical power feed means, etc., is
operable in response to the control signals from (directly or
indirectly, as discussed above) associated thermal controller 208.
The control signal may, e.g., alter the operating state of thermal
device 206, such as increasing or reducing the power supplied to
thermal device 206, initiating, terminating or otherwise adjusting
the flow of heating or cooling fluid to or through thermal device
206, etc. For example, if the thermal device is a heater, reducing
the power may reduce the heat emitted by thermal device 206. In
other embodiments, the control signal may merely switch the power
state of thermal device 206 between an "ON" state and an "OFF"
state.
[0030] Returning to FIG. 2a, manifold 204 comprises thermal device
212 that is associated with thermal controller 214 and thermal
device 216 that is associated with thermal controller 218.
Therefore, manifold 204 comprises at least two thermal control
zones or at least a portion of each of at least two control zones.
As seen in FIG. 2a, portions of manifold 202 are in close proximity
to thermal device 212 and thermal controller 214 of manifold 204.
In fact, location 220 of manifold 204 is proximate to portions of
manifold 202. Therefore, in one embodiment, portions of manifold
202 may be considered in the same control zone as portions of 204.
Alternatively, the manifold system can be divided into a different
set of thermal control zones. In select embodiments, the thermal
control zones are symmetric with respect to each other, whereas in
other embodiments, the control zones are determined by a myriad of
factors. It will be within the ability of those of ordinary skill
in the art, given the benefit of this disclosure, to suitably
divide a manifold or other apparatus into multiple control zones
for design or analysis in accordance with the finite element
methods disclosed here.
[0031] Also located on manifold 204 of model 200 is thermal device
216 and thermal controller 218, which both belong to the same
control zone, specifically, a control zone different from that of
thermal device 212 and thermal controller 214. In addition to being
primarily thermally controlled by its own thermal device and
thermal controller, the temperature and/or other thermal properties
or performance of each such control zones are affected by the
inputs of the thermal device of the other control zone as well as
possibly the inputs of thermal device 206.
[0032] As shown, model 200 is in graphical form, however, one
skilled in the art, given the benefit of this disclosure, will
readily appreciate that the model and any information relating to
the model provided in step 102 may be in any form, including
graphical, numerical, binary, and combinations thereof so long as
the model includes or represents or is based on or otherwise
incorporates at least one aspect of the physical geometry of the
system which it represents. The received data may represent a
2-dimensional model or a more complex 3-dimensional model.
[0033] Returning to FIG. 1, at least one input regarding at least
one material of the apparatus or system represented by the model
utilized in step 102 (such as model 200), is provided in step 104.
The input may be a manual user-input providing information
regarding one or more materials, chemicals or compositions utilized
or intended to be utilized to make the physical system. The
information may, for example, be one or more physical or
performance properties, e.g., thermal conductivity, heat capacity
or thermal capacitance, specific heat capacity (also called more
properly "mass-specific heat capacity" or more loosely "specific
heat"), boundary conditions, or the like, etc. In one embodiment
where the model is directed towards a system that is already
designed, the materials may be detected by automated mechanisms or
automatically submitted to the model. In still yet further
embodiments, the input is provided as part of step 102. The input
may be in any suitable form, e.g., textual, numerical, binary or
combinations thereof, and optionally is converted to another form
for use within the process.
[0034] The input may be the value of a single physical or
performance property or a value representing multiple physical or
performance properties in any suitable combination. Multiple inputs
may be received regarding the same material, such as the material's
composition, heat capacity, specific heat capacity, thermal
conductivity, density, strength, etc. In other exemplary
embodiments, only one input is received and may then be associated
with several qualities of the material, e.g., qualities that are
stored on a computer-readable medium. In yet other exemplary
embodiments, one or more inputs are received for multiple materials
that make up the apparatus or system. For example, manifold 202 of
model 200 may comprise one or more materials not included in
manifold 204, and inputs may be received for each.
[0035] In step 106, a mesh for the model, such as model 200 is
defined. As readily known to those skilled in the art, a plurality
of nodes are mapped or otherwise distributed around the modeled
topography of the system or select areas of the system of interest.
The nodes are interconnecting, wherein each node is modeled to be
in communication with and to be affected by any changes to at least
one other node it is in communication with. The quantity,
distribution, and density of the nodes for any given determination
(i.e., analysis or design) in accordance with the methods and
systems disclosed here may be determined by those of ordinary skill
in the art given the benefit of this disclosure, based on factors,
including but not limited to, the desired accuracy of the result,
geometry of one or more components of the apparatus being analyzed,
the material(s) used in the apparatus or its component(s), the
design of the apparatus or system, and/or other areas of specific
concern applicable to the particular analysis. In certain exemplary
embodiments, each control zone is represented by a fixed number of
nodes ranging from 1 to a maximum quantity, yet in other
embodiments, different quantities of nodes are assigned to various
control zones based upon one or more factors, such as those
described above. In certain exemplary embodiments, the mesh is
created automatically by computer-executable instructions stored on
a computer-readable medium. In certain such embodiments, manual
manipulation may be conducted to further refine the mesh. Those
skilled in the art, given the benefit of this disclosure, will be
well able to implement suitable procedures for defining and
manipulating a mesh as used herein.
[0036] FIG. 2b shows a perspective view of a portion of exemplary
model of a manifold that may be utilized according to select
embodiments of the invention. As shown, the exemplary portion of
model 250 comprises a mesh 252 that, when viewed graphically,
appears similar to a net or spider-web that covers the outer
surface of the model 250. The mesh 252 divides the model 250 into
discrete elements that are all interconnected, with proximate nodes
being in contact with neighboring nodes. As presented in the
exemplary example, the nodes are not necessarily symmetrically
spaced, and have different shaped boundaries. As further seen with
exemplary mesh 252, some elements may be larger than others
elements in addition to having different shapes.
[0037] In step 108, one or more factors relating to boundary
conditions may be introduced into process. As used herein, boundary
conditions may encompass or include any known parameters that
introduce, remove, alter, and/or affect the distribution of a
thermal parameter in the system. For example, the specific location
of a nearby conductive manifold or other mechanism that affects a
temperature condition may be inputted into the system to compensate
for any heat loss due to the conductive manifold. As used
throughout the specification, the term heat loss may encompass a
positive or negative value to indicate a gain of heat energy or the
loss of heat energy. Also, the outer boundaries of the manifold may
be exposed to ambient air temperatures at one location while
exposed to extreme temperatures at another, such as being in close
proximity to another manifold or section of the system that is
known to affect one or more temperature parameters.
[0038] Yet in another embodiment, a specific protrusion or attached
component, made of the same or a different material as one or more
manifolds, may affect one or more temperature parameters. For
example, looking to FIG. 2a, contact plate 226 is operatively
attached to manifold 202. In one embodiment, the heat lost by
contact plate 226 is readily known or may be estimated and
therefore may be provided to the system as an input as a known
boundary condition. As one skilled in the art will readily
appreciate given the disclosure provided herein, according to one
embodiment, one or more boundary conditions may initially be an
unknown factor that may be calculated according to the teachings of
select aspects of the invention. For example, in one embodiment, a
temperature parameter of several control zones may be known in a
manifold that has already been designed and/or manufactured.
However, it would be desirable to determine the effect of a
boundary condition, such as the addition of contact plate 226, may
have upon the system. As demonstrated from the foregoing, there may
be a plurality of boundary conditions that may differ across
different portions of one or more components of an apparatus. As
would be further appreciated by one skilled in the art, one or more
boundary conditions may be considered in step 104, when the
material data is provided.
[0039] In step 110, the determination of thermal correlation
between a plurality of zones is initiated. One exemplary method of
determining the thermal correlation is shown by way of the
illustrative thermal influence matrix of FIG. 3a. The exemplary
thermal matrix 300 is formed by an [n.times.n] matrix, wherein "n"
equals the number of control zones. Exemplary thermal matrix 300
provides exemplary data to illustrate one process according to
these aspects of the invention. As seen with column 302, a fixed
simulation process is conducted. The term fixed simulation
signifies that the number of simulations performed is equal to the
number of thermal control zones (n=# of simulations). Columns 304,
306 and 308 represent the specific control zones Htr_1, Htr_2, and
Htr_3, respectively, which for example, may represent heaters 206,
212, and 216 shown in FIG. 2a. As discussed above, however, the
control zones may be any set of areas that each has at least one
thermal input and at least one thermal output. The thermal input
for a given zone may be, for example, a value corresponding or
correlating to the rate of heat loss from that zone under operating
conditions at a given temperature, e.g., at the temperature set
point of the thermal controller of the zone in question. In a
typical application, therefore, the temperature may, for example,
be the temperature at that zone's thermal controller, recognizing
that a temperature gradient may exist in the zone from the location
of the thermal controller to any other location in the zone. The
thermal input for a given zone may be, for example, a value
corresponding or correlating to the rate of heat input into that
zone by the thermal device of that zone, upon actuation, under
operating conditions.
[0040] The thermal relationship between each zone may be quantified
by applying an arbitrary value for a thermal parameter to one
particular zone, while the other zones are unaltered. For each
simulation, which will be equal to the number of control zones
tested, the arbitrary value will remain the same. For example,
looking to simulation 1, designated by row 310, value "q" is
applied to control zone Htr_1 while the two other exemplary control
zones remain unaltered. For simulation 2, designated by row 312,
value "q" is applied to control zone Htr_2, while Htr_1 and Htr_3
are unaltered, and looking to simulation 3, designated by row 314,
"q" is applied to Htr_3 and the other two control zones are left
unaltered. Thus, for each simulation, "q" is applied to a single
control zone that is different than the previous simulation, where
the number of simulations equals the number of thermal control
zones. In other implementations, another value that is different
than "q" may be applied, but the same value will be applied for
each simulation, albeit at different control zones.
[0041] Columns 316, 318 and 320 provide the results for each
control zone per simulation using the nomenclature Txy, where T
designates a temperature value is given, "x" designates the control
zone for which T is being measured and "y" designates the control
zone that is causing the provided value. For example, in Simulation
#1 where "q" was only applied to control zone 1 (Htr_1), the effect
of "q" was measured for each control zone, including the zone for
which it was applied. As seen in column 316, the value is T11, thus
providing the temperature at control zone 1 from the application of
"q" at Htr_1. Column 318 for the same simulation has a value T21,
thus providing the temperature at control zone 2 from the
application of "q" at Htr_1 and column 310 has a value of T31, thus
providing the temperature at control zone 3 from the application of
"q" at Htr_1. As predicted, for Simulation #2, the "y" will always
be 2 and accordingly, will always be 3 for the Simulation #3.
[0042] Those skilled in the art will readily understand that any
thermal parameters, such as those described in this application, as
well as those known in the art, may be utilized without departing
from the scope of the disclosure. To better acquaint the reader
with a real-world example, FIG. 3b is provided as an exemplary
temperature matrix of a manifold having three control zones
providing exemplary data to illustrate another process according to
select embodiments of the invention. As seen in FIG. 3b, "q" is set
to 0.1 W/mm.sup.2, where "q" is the arbitrary heat flux value
corresponding to the heater for each of the three zones (during the
3 simulations). For each of the three simulations, the temperature
is recorded at each thermal controller's location (1 per control
zone) and the influence matrix shown on the right side of FIG. 3b
may be calculated with the provided data, wherein each column
provides the simulated temperature at each thermal controller due
to the heat flux applied to the heater designated in that
particular column.
[0043] Step 112 may then be implemented, where a thermal parameter
for each control zone is applied. According to one embodiment, the
thermal parameter is the temperature of a section of the manifold
or fluid traveling within the manifold at a specific location. For
example, as shown in FIG. 2a, thermal controller 208 may provide a
temperature value at its location. In other embodiments, thermal
controller 208 receives or measures the thermal parameter of a
compound, such as a liquid in channel 210, as the liquid travels
through a portion of the control zone. One skilled in the art
understands that any parameter relating to a thermal property that
is known regarding a plurality of individual control zones of
interest may be utilized in step 112.
[0044] At step 114, the influence matrix may be utilized to obtain
a result of the linear thermal relationship of an unknown thermal
parameter for each control zone within the influence matrix. Using
the manifold model 200 of FIG. 2a and influence matrix 300 of FIG.
3 as an example, in one embodiment Equation (1) may be utilized to
determine the steady-state heat conduction with the three zones
when the control zone input is a temperature, such as heat produced
by thermal device 206, and the control zone output is a heat flux
(which is unknown)
Equation ( 1 ) : ##EQU00001## T tc ( 1 3 ) = { I temp } .times. q (
1 3 ) ##EQU00001.2##
[0045] Looking to Equation 1, "T" is the temperature at the thermal
controller, "q" is the heat flux, and "I" represents the influence
matrix. In the exemplary embodiment, the input parameter "T" is
known and provided from step 112, therefore, the equation is to be
solved for the output parameter "q". Thus, in one embodiment, the
equation may be used to determine how much heat needs to come from
a heater to get a certain temperature at a thermal controller. As
one skilled in the art will readily appreciate, derivations of
Equation 1 may be utilized to obtain a result of the linear thermal
relationship of the unknown thermal parameters for each control
zone within the influence matrix without departing from the scope
of the recited aspects of the invention. In one embodiment, FIG. 3a
may be utilized to determine output parameter "q".
Equation ( 2 ) : ##EQU00002## { q 1 q 2 q 3 } = [ T 11 T 12 T 13 T
21 T 22 T 23 T 31 T 32 T 33 ] - 1 { Tset - Tplate Tset - Tplate
Tset - Tplate } ##EQU00002.2##
Utilizing the "real-world data" presented in the exemplary
influence matrix of FIG. 3b, Equation 2 may be expressed as:
{ q 1 q 2 q 3 } = [ 680 684 293 255 846 636 63 232 1049 ] - 1 { 288
- 82 288 - 82 288 - 82 } ##EQU00003##
where Tset=288 and Tplate=82, thus providing a result of:
{ q 1 q 2 q 3 } = [ 0.0163 0.0065 0.0172 ] W / mm 2
##EQU00004##
[0046] One skilled in the art will readily understand with aid of
this disclosure derivations of Equation 2 that will adequately
determine "q" or any other thermal value. For example, in one
embodiment, {-Tplate} may be removed from the equation if delta T
is not required or desired. In yet further embodiments, other
components and computations may be added to the equation being
utilized to tailor the process for specific purposes.
[0047] Once the thermal parameter, such as the heat flux is
determined, step 116 may then be applied to the FEA model to
determine the thermal profile of the system or portion of the
system in question. For example, the heat flux obtained for each
control zone may be applied to the heaters for the respective
control zones in a finite element analysis to simulate the correct
thermal profile. FIG. 4 is a perspective view of one exemplary
thermal profile of a manifold system utilizing the data shown in
FIG. 3b. Yet in other embodiments, where a new system may be in the
process of being designed, the profile obtained may be useful in
further development or design of the system, such as a
multi-component manifold. Indeed, step 116 may be initiated to
determine why a manifold already manufactured is not operating at
optimal level or otherwise malfunctioning. In one such embodiment,
the results of step 116 may be utilized to determine how to fix the
deficiency. For example, if one control zone's thermal properties
are adversely affecting the thermal properties of another control
zone, a thermal device may be added to remedy or fix the
deficiency. In yet another embodiment, an existing thermal device
may be altered to fix the deficiency.
[0048] The foregoing detailed description of preferred embodiments
is intended to be exemplary of the invention and illustrative.
Modifications of the embodiments disclosed and alternative
embodiments will be apparent to those skilled in the art in view of
the above, and all such modifications and alternatives are intended
to be within the scope of appropriate ones of the following claims.
The appended claims are intended to cover all such modifications
and alternative embodiments. It should be understood that the use
of a singular indefinite or definite article (e.g., "a," "an,"
"the," etc.) in this disclosure and in the following claims follows
the traditional approach in patents of meaning "at least one"
unless in a particular instance it is clear from context that the
term is intended in that particular instance to mean specifically
one and only one. Likewise, the term "comprising" is open ended,
not excluding additional items, features, and elements.
* * * * *