U.S. patent application number 12/110225 was filed with the patent office on 2008-12-25 for temperature control device.
This patent application is currently assigned to TOKYO ELECTRON LIMITED. Invention is credited to Hiroshi ITAFUJI, Yoshiyuki KOBAYASHI, Norio KOKUBO, Koichi MURAKAMI, Kazuya NAGASEKI, Ryo NONAKA, Yoshihisa SUDOH.
Application Number | 20080314564 12/110225 |
Document ID | / |
Family ID | 40054326 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080314564 |
Kind Code |
A1 |
NAGASEKI; Kazuya ; et
al. |
December 25, 2008 |
TEMPERATURE CONTROL DEVICE
Abstract
A temperature control device controls the temperature of a
controlled object by circulating a fluid in a temperature
adjustment unit arranged near the controlled object. The
temperature control device comprises a heating pathway that heats
and circulates the fluid in the temperature adjustment unit, a
cooling pathway that cools and circulates the fluid in the
temperature adjustment unit, a bypass pathway that does not pass
the fluid through the heating pathway and cooling pathway, but
circulates the fluid in the temperature adjustment unit, and
adjustment means that adjust a flow ratio of the fluid that is
supplied from the heating pathway, cooling pathway, and bypass
pathway to the temperature adjustment unit via a confluence unit
that combines these flows. The adjustment means are provided on a
downstream side of each of the heating pathway, the cooling
pathway, and the bypass pathway and on the upstream side of the
confluence unit.
Inventors: |
NAGASEKI; Kazuya;
(Nirasaki-shi, JP) ; KOBAYASHI; Yoshiyuki;
(Nirasaki-shi, JP) ; MURAKAMI; Koichi;
(Nirasaki-shi, JP) ; NONAKA; Ryo; (Nirasaki-shi,
JP) ; SUDOH; Yoshihisa; (Komaki-shi, JP) ;
ITAFUJI; Hiroshi; (Komaki-shi, JP) ; KOKUBO;
Norio; (Komaki-shi, JP) |
Correspondence
Address: |
Beyer Law Group LLP
P.O. BOX 1687
Cupertino
CA
95015-1687
US
|
Assignee: |
TOKYO ELECTRON LIMITED
Tokyo
JP
CKD CORPORATION
Komaki-shi
JP
|
Family ID: |
40054326 |
Appl. No.: |
12/110225 |
Filed: |
April 25, 2008 |
Current U.S.
Class: |
165/104.31 |
Current CPC
Class: |
G05D 23/19 20130101 |
Class at
Publication: |
165/104.31 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2007 |
JP |
2007-118071 |
Claims
1. A temperature control device that controls the temperature of a
controlled object by circulating a fluid in a temperature
adjustment unit arranged near the controlled object, comprising: a
heating pathway that heats and circulates the fluid in the
temperature adjustment unit, a cooling pathway that cools and
circulates the fluid in the temperature adjustment unit, a bypass
pathway that does not pass the fluid through the heating pathway
and cooling pathway, but circulates the fluid in the temperature
adjustment unit, and adjustment means that adjust a flow ratio of
the fluid that is supplied from the heating pathway, cooling
pathway, and bypass pathway to the temperature adjustment unit via
a confluence unit that combines these flows, wherein the adjustment
means are provided on a downstream side of each of the heating
pathway, the cooling pathway, and the bypass pathway and on the
upstream side of the confluence unit.
2-18. (canceled)
19. The temperature control device according to claim 1, wherein
the bypass pathway is shared between the heating pathway and the
cooling pathway.
20. The temperature control device according to claim 1, wherein an
effusion pathway that diverts the fluid from the adjustment means
and effuses the fluid is provided on the upstream side of the
heating pathway and the cooling pathway.
21. The temperature control device according to claim 1, further
comprising a pump that draws in the fluid downstream from the
temperature adjustment unit, and discharges the fluid to the
heating pathway, the cooling pathway, and the bypass pathway.
22. The temperature control device according to claim 1, wherein a
storage means that stores the fluid is provided on the upstream
side of each of the heating pathway, the cooling pathway, and the
bypass pathway, and on the downstream side of the temperature
adjustment unit, and the storage means absorbs a change in the
volume of the fluid due to a change in temperature.
23. The temperature control device according to claim 1, further
comprising a manipulating means that manipulates the adjustment
means so as to control the temperature of the fluid inside and/or
near the temperature adjustment unit to a target value.
24. The temperature control device according to claim 23, further
comprising a supply temperature detection means that detects the
temperature of the fluid inside and/or near the temperature
adjustment unit, and the manipulating means feedback controls the
value detected by the supply temperature detection means to the
target value.
25. The temperature control device according to claim 24, wherein
the adjustment means adjusts the downstream side flow dimensions of
each of the heating pathway, the cooling pathway, and the bypass
pathway, and the manipulating means comprises a conversion means
that converts an amount based upon a degree of deviation from the
target value of the detected value to manipulating variable of the
flow ratio of each of the heating pathway, the cooling pathway, and
the bypass pathway.
26. The temperature control device according to claim 24, further
comprising a bypass temperature detecting means that detects the
temperature of the bypass pathway, wherein instead of performing
feedback control, for a predetermined period of time after a change
in the target value, the manipulating means manipulates the
adjustment means so as to perform open loop control of the
temperature of the fluid inside and/or near the temperature
adjustment unit based upon the value detected by the bypass
temperature detecting means.
27. The temperature control device according to claim 26, wherein
the adjustment means adjusts the downstream side flow dimensions of
each of the heating pathway, the cooling pathway, and the bypass
pathway, and for the predetermined period, the manipulating means
open loop controls the temperature of the temperature adjustment
unit to the target value by manipulating the adjustment means so as
to adjust the flow ratio of the bypass pathway and the cooling
pathway if the temperature of the fluid inside the bypass pathway
is higher than the target value, and open loop controls the
temperature of the temperature adjustment unit to the target value
by manipulating the adjustment means so as to adjust the flow ratio
of the bypass pathway and the heating pathway if the temperature of
the fluid inside the bypass pathway is lower than the target
value.
28. The temperature control device according to claim 23, further
comprising a transient target value setting means that changes the
target value, when a desired temperature of the temperature
adjustment unit is changed, so as to be larger than the change of
the desired value.
29. The temperature control device according to claim 26, further
comprising an open loop control adjustment support means that
outputs prompt signals to select any one of a plurality of
selections relating to at least one of open loop control gain, the
period of time that open loop control is to continue, and the
target value during open loop control, and performs temperature
control in accordance with the selected value.
30. The temperature control device according to claim 23, wherein
the adjustment means adjusts the downstream side flow dimensions of
each of the heating pathway, the cooling pathway, and the bypass
pathway, and the manipulating means prevents the flow ratio of the
heating pathway and the cooling pathway that are adjusted by the
adjustment means from reaching zero when the temperature inside
and/or near the temperature adjustment unit is in a steady
state.
31. A temperature control device that controls the temperature of a
controlled object by circulating a fluid in a temperature
adjustment unit arranged near the controlled object, comprising: a
heating pathway that heats and circulates the fluid in the
temperature adjustment unit, a cooling pathway that cools and
circulates the fluid in the temperature adjustment unit, a bypass
pathway that does not pass the fluid through the heating pathway
and cooling pathway, but circulates the fluid in the temperature
adjustment unit, and adjustment means that adjust the downstream
side flow dimensions of each of the heating pathway, cooling
pathway, and bypass pathway.
32. The temperature control device according to claim 31, further
comprising a manipulating means that manipulates the adjustment
means so as to control the temperature of the fluid inside and/or
near the temperature adjustment unit to a target value, and a
supply temperature detection means that detects the temperature of
the fluid inside and/or near the temperature adjustment unit,
wherein the manipulating means feedback controls the value detected
by the supply temperature detection means to the target value.
33. The temperature control device according to claim 31, further
comprising a manipulating means that manipulates the adjustment
means so as to control the temperature of the fluid inside and/or
near the temperature adjustment unit to a target value, wherein the
manipulating means comprises a conversion means that converts an
amount based upon a degree of deviation from the target value of
the detected value to manipulating variable of a path dimension for
each of the heating pathway, the cooling pathway, and the bypass
pathway.
34. The temperature control device according to claim 31, further
comprising a manipulating means that manipulates the adjustment
means so as to control the temperature of the fluid inside and/or
near the temperature adjustment unit to a target value, wherein for
the predetermined period, the manipulating means open loop controls
the temperature of the temperature adjustment unit to the target
value by manipulating the adjustment means so as to adjust the path
dimensions of the bypass pathway and the cooling pathway if the
temperature of the fluid inside the bypass pathway is higher than
the target value, and open loop controls the temperature of the
temperature adjustment unit to the target value by manipulating the
adjustment means so as to adjust the path dimensions of the bypass
pathway and the heating pathway if the temperature of the fluid
inside the bypass pathway is lower than the target value.
35. The temperature control device according to claim 31, further
comprising a manipulating means that manipulates the adjustment
means so as to control the temperature of the fluid inside and/or
near the temperature adjustment unit to a target value, wherein the
manipulating means prevents the path dimensions of the heating
pathway and the cooling pathway that are adjusted by the adjustment
means from reaching zero when the temperature inside and/or near
the temperature adjustment unit is in a steady state.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a temperature control
device that controls the temperature of a controlled object by
circulating a fluid in a temperature adjustment unit arranged near
the controlled object.
BACKGROUND ART
[0002] FIG. 12 shows this type of temperature control device. Fluid
inside a storage tank 100 is drawn by a pump 102, and is discharged
to a heating unit 104. The heating unit 104 is comprised of a
heater, and is capable of heating the fluid to be supplied to a
temperature adjustment unit 106. The fluid that has passed through
the temperature adjustment unit 106 will be supplied to a cooling
unit 108. The cooling unit 108 is capable of cooling the fluid to
be discharged to the storage tank 100.
[0003] The temperature adjustment unit 106 is capable of supporting
a controlled object, and the temperature of the controlled object
that is supported by the temperature adjustment unit 106 will be
controlled by adjusting the temperature of the fluid supplied to
the temperature adjustment unit 106. Here, when there is a need to
raise the temperature of the controlled object, the fluid in the
cooling unit 108 will not be cooled, and the fluid in the heating
unit 10 will be heated. In contrast, when there is a need to lower
the temperature of the controlled object, the fluid in the cooling
unit 108 will be cooled, and the fluid in the heating unit 10 will
not be heated. In this way, the temperature of the controlled
object can be controlled at a desired level.
[0004] Note that a conventional temperature control device may be
one other than that shown in FIG. 12, e.g., the device disclosed in
the following Patent Reference 1.
[0005] [Patent Reference 1] Japanese Published Patent Application
No. 2000-89832.
SUMMARY OF THE INVENTION
[0006] The aforementioned temperature control device requires a
long period of time in order to change to the desired temperature
of a controlled object. When there is a need to cool the
temperature of a controlled object, it will be necessary to stop
heating with the heating unit 104 and start cooling with the
cooling unit 108. However, even after heating with the heating unit
104 is stopped, high temperature fluid will be supplied from the
heating unit 104 for a period of time due to residual heat. In
addition, even though cooling has begun with the cooling unit 108,
it will take time for the fluid to be actually cooled, and an even
longer period of time will be needed to reduce the temperature of
the fluid inside the storage tank 100. Because of this, the
temperature inside the temperature adjustment unit 106 cannot be
quickly changed, and thus the temperature of the controlled object
cannot be quickly changed.
[0007] An object of the present invention is to provide a
temperature control device that can, when controlling the
temperature of a controlled object by circulating a fluid in a
temperature adjustment unit arranged near the controlled object,
quickly achieve the desired temperature of the controlled
object.
[0008] An aspect of the invention of means 1 is a temperature
control device that controls the temperature of a controlled object
by circulating a fluid in a temperature adjustment unit arranged
near the controlled object, and can comprise a heating pathway that
heats and circulates the fluid in the temperature adjustment unit,
a cooling pathway that cools and circulates the fluid in the
temperature adjustment unit, a bypass pathway that does not pass
the fluid through the heating pathway and cooling pathway, but
circulates the fluid in the temperature adjustment unit, and
adjustment means that adjust a flow ratio of the fluid that is
supplied from the heating pathway, cooling pathway, and bypass
pathway to the temperature adjustment unit via a confluence unit
that combines these flows. The adjustment means may be provided on
a downstream side of each of the heating pathway, the cooling
pathway, and the bypass pathway and on the upstream side of the
confluence unit.
[0009] Means 1 can quickly change the temperature of the fluid
supplied to the temperature adjustment unit by adjusting the flow
ratio supplied to the temperature adjustment unit via the heating
pathway, the cooling pathway, and the bypass pathway. In
particular, because the flow ratio is adjusted on the downstream
side of the heating pathway, the cooling pathway, and the bypass
pathway, and on the upstream side of the confluence unit, the
distance between the flow ratio adjustment point and the
temperature adjustment unit can be considerably shortened, and the
temperature of the fluid supplied to the temperature adjustment
unit can be all the more quickly changed. Because of this, when the
temperature of the controlled object is to be controlled, the
temperature of the controlled object can quickly achieve the
desired level.
[0010] Note that it is preferable that the path dimensions of the
confluence unit is small to the greatest extent possible so as not
to reduce the flow rate of the fluid flowing therein via the
heating pathway, the cooling pathway, and the bypass pathway. Here,
the flow rate of the fluid is the forward speed of the fluid in the
direction of circulation.
[0011] In addition, the adjustment means may adjust the individual
flow ratio of the fluid that is supplied to the temperature
adjustment unit via the heating pathway, the cooling pathway, and
the bypass pathway.
[0012] An aspect of the invention of means 2 is a temperature
control device that controls the temperature of a controlled object
by circulating a fluid in a temperature adjustment unit arranged
near the controlled object, and can comprise a heating pathway that
heats and circulates the fluid in the temperature adjustment unit,
a cooling pathway that cools and circulates the fluid in the
temperature adjustment unit, a bypass pathway that does not pass
the fluid through the heating pathway and cooling pathway, but
circulates the fluid in the temperature adjustment unit, and
adjustment means that adjust the downstream side flow dimensions of
each of the heating pathway, cooling pathway, and bypass
pathway.
[0013] Means 2 can adjust the flow ratio supplied to the
temperature adjustment unit via the heating pathway, the cooling
pathway, and the bypass pathway by adjusting the respective
downstream side flow dimensions of the heating pathway, the cooling
pathway, and the bypass pathway. Thus, the temperature of the fluid
supplied to the temperature adjustment unit can be quickly changed.
Because of this, when the temperature of the controlled object is
to be controlled, the temperature of the controlled object can
quickly achieve the desired level.
[0014] In an aspect of the invention of means 3, the bypass pathway
is shared with the heating pathway and the cooling pathway.
[0015] Means 3 can employ a shared bypass pathway when fluid is to
be supplied from the heating pathway and the bypass pathway to the
temperature adjustment unit, and when fluid is to be supplied from
the cooling pathway and the bypass pathway to the temperature
adjustment unit. Because of this, compared to situations in which
different bypass pathways must be used, the structure of the
temperature control device can be simplified.
[0016] In an aspect of the invention of means 4, an effusion
pathway that diverts the fluid from the adjustment means and
effuses the fluid can be provided on the upstream side of the
heating pathway and the cooling pathway.
[0017] When the supply of fluid from the heating pathway and the
cooling pathway to the temperature adjustment unit is prohibited, a
temperature gradient will be created between the downstream side of
the adjustment means and the prohibited pathway. Thus, due to the
effects of the temperature gradient in the fluid to be supplied to
the temperature adjustment unit immediately after the prohibition
is eliminated, a longer period of time may be needed for the
temperature of the temperature adjustment unit to achieve the
desired temperature. By including the effusion pathways in means 4,
temperature gradients upstream of the discharge pathway can be
suitably inhibited, and the temperature of the temperature
adjustment unit can quickly achieve the desired temperature.
[0018] Note that means 4 may be provided with heating side
temperature detecting means that detects the temperature upstream
from the adjustment means along the heating pathway, and cooling
side temperature detecting means that detects the temperature
upstream from the adjustment means along the cooling pathway. In
this case, by providing the effusion pathways, the effect of
temperature gradients on the detecting means caused by prohibiting
the discharge of fluid from the heating pathway and the cooling
pathway can be suitably inhibited.
[0019] An aspect of the invention of means 5 can comprise a pump
that draws in the fluid downstream from the temperature adjustment
unit, and discharges the fluid to the heating pathway, the cooling
pathway, and the bypass pathway.
[0020] Means 5 can use the pump to circulate the fluid. In
particular, by arranging a pump upstream from the heating pathway,
the cooling pathway, and the bypass pathway, the length of the
fluid pathway between the adjustment means and the temperature
adjustment unit can be shortened compared to when arranged
downstream from the heating pathway, the cooling pathway, and the
bypass pathway and upstream from the temperature adjustment unit.
Because of this, the fluid supplied from the adjustment means can
be quickly delivered to the temperature adjustment unit, and the
temperature of the temperature adjustment unit can quickly achieve
the desired temperature.
[0021] An aspect of the invention of means 6 can be provided with a
storage means that stores the fluid on the upstream side of each of
the heating pathway, the cooling pathway, and the bypass pathway,
and on the downstream side of the temperature adjustment unit. The
storage means absorbs a change in the volume of the fluid due to a
change in temperature.
[0022] When the volume of the fluid is temperature dependent, the
circulation of the fluid may be hindered by a change in the volume
caused by a change in the temperature of the fluid. Because means 6
has a function in which the storage means absorbs a change in the
volume, the circulation of the fluid can be suitably maintained
when the volume of the fluid changes. Moreover, by arranging the
storage means upstream from the heating pathway, the cooling
pathway, and the bypass pathway, the length of the fluid pathway
between the adjustment means and the temperature adjustment unit
can be shortened compared to when the storage means is arranged
downstream from the heating pathway, the cooling pathway, and the
bypass pathway and upstream from the temperature adjustment
unit.
[0023] An aspect of the invention of means 7 can comprise a
manipulating means that manipulates the adjustment means so as to
control the temperature of the fluid inside and/or near the
temperature adjustment unit to a target value.
[0024] In means 7, the temperature of the temperature adjustment
unit can be adjusted by providing the manipulating means at desired
level.
[0025] An aspect of the invention of means 8 may comprise a supply
temperature detection means that detects the temperature of the
fluid inside and/or near the temperature adjustment unit, and the
manipulating means feedback controls the value detected by the
temperature detection means to the target value.
[0026] With means 8, the detected value will be adjusted to the
target value with a high degree of accuracy because the
manipulating means performs feedback control.
[0027] In an aspect of the invention of means 9, the adjustment
means can adjust the downstream side flow dimensions of each of the
heating pathway, the cooling pathway, and the bypass pathway. The
manipulating means can comprise a conversion means that converts an
amount based upon a degree of deviation from the target value of
the detected value to manipulating variable of a path dimension for
each of the heating pathway, the cooling pathway, and the bypass
pathway.
[0028] By providing the conversion means in means 9, the degree of
deviation of the detected value from the target value can be simply
quantified with a single amount, and the path dimensions of the
three pathways can be adjusted (changed) based on this quantified
amount.
[0029] Note that it is preferable for the conversion means to
change the path dimensions of the cooling pathway and the bypass
pathway with respect to the change of the degree of deviation when
the detected value is larger than the target value, and change the
path dimensions of the heating pathway and the bypass pathway with
respect to the change of the degree of deviation when the detected
value is smaller than the target value.
[0030] An aspect of the invention of means 10 may comprise a bypass
temperature detecting means that detects the temperature of the
bypass pathway. In means 10, instead of performing feedback
control, for a predetermined period of time after a change in the
target value, the manipulating means manipulates the adjustment
means so as to perform open loop control of the temperature of the
fluid inside and/or near the temperature adjustment unit based upon
the value detected by the bypass temperature detecting means.
[0031] When the target value is changed, an increase in the gain of
the feedback control will be requested in order to quickly place
the temperature of the detected value at the target value by means
of that control. When the gain of the control increases, there will
be an increase in the amount of variation in the detected value
above and below the target value. Thus, with feedback control,
there is a mutual trade-off between an increase in responsiveness
and the inhibition of the amount of variation. With means 10,
because open loop control is performed instead of feedback control
over a predetermined period of time from when the target value is
changed, responsiveness during the change in the target value can
be increased, even if the feedback control was set so as to inhibit
the amount of variation in the detected value above and below the
target value.
[0032] In an aspect of the invention of means 11, the adjustment
means may adjust the downstream side flow dimensions of each of the
heating pathway, the cooling pathway, and the bypass pathway. For
the predetermined period, the manipulating means open loop controls
the temperature of the temperature adjustment unit to the target
value by manipulating the adjustment means so as to adjust the path
dimensions of the bypass pathway and the cooling pathway if the
temperature of the fluid inside the bypass pathway is higher than
the target value, and open loop controls the temperature of the
temperature adjustment unit to the target value by manipulating the
adjustment means so as to adjust the path dimensions of the bypass
pathway and the heating pathway if the temperature of the fluid
inside the bypass pathway is lower than the target value.
[0033] Means 11 can reduce the amount of energy consumption,
compared to when the heating pathway is used, by manipulating the
path dimensions of the bypass pathway and the cooling pathway when
the temperature of the fluid inside the bypass pathway is higher
than the target value. In addition, means 11 can reduce the amount
of energy consumption, compared to when the cooling pathway is
used, by manipulating the path dimensions of the bypass pathway and
the heating pathway when the temperature of the fluid inside the
bypass pathway is lower than the target value.
[0034] An aspect of the invention of means 12 further a transient
target value setting means that changes the target value, when a
desired temperature of the temperature adjustment unit is changed,
so as to be larger than the change of the desired value.
[0035] In order for the temperature of the temperature adjustment
unit to achieve the target value after the target value is changed,
it will be necessary to change the temperature of the temperature
adjustment unit by means of temperature-adjusted fluid, and thus a
response lag will be created in achieving the target value.
Furthermore, in order to change the temperature of the controlled
object, the exchange of heat energy between the controlled object
and the temperature adjustment unit must occur after the
temperature of the temperature adjustment unit is changed, and thus
the response lag in the change in temperature of the controlled
object will become all the more prominent. Here, when the desired
temperature is changed, means 12 can quickly change the temperature
of the temperature adjustment unit and the controlled object to the
desired temperature by making the change in the target value larger
than the desired change.
[0036] An aspect of the invention of means 13 may comprise an open
loop control adjustment support means that outputs prompt signals
to select any one of a plurality of selections relating to at least
one of open loop control gain, the period of time that open loop
control is to continue, and the target value during open loop
control, and performs temperature control in accordance with the
selected value.
[0037] With open loop control, the optimal setting of the gain, the
period of time control is to continue, and the target value, will
depend on the controlled object. Thus, by fixing these parameters
from the start in the temperature control device, open loop control
may not be able to be performed on the controlled object. By
providing the adjustment support means, means 13 can reduce the
amount of work performed when a user of the temperature control
device applies these parameters in response to the controlled
object.
[0038] In an aspect of the invention of means 14, the adjustment
means can adjust the downstream side flow dimensions of each of the
heating pathway, the cooling pathway, and the bypass pathway. The
manipulating means prevents the path dimensions of the heating
pathway and the cooling pathway that are adjusted by the adjustment
means from reaching zero when the temperature inside and/or near
the temperature adjustment unit is in a steady state.
[0039] When the supply of fluid from the heating pathway and the
cooling pathway to the temperature adjustment unit is prohibited, a
temperature gradient will be created between the downstream side of
the adjustment means and the prohibited pathway. Thus, due to the
effects of the temperature gradient in the fluid to be supplied to
the temperature adjustment unit immediately after the prohibition
is eliminated, a longer period of time may be needed for the
temperature of the temperature adjustment unit to achieve the
desired temperature. When the temperature of the temperature
adjustment unit is in a steady state, means 14 can suitably inhibit
temperature gradients, and can more quickly place the temperature
of the temperature adjustment unit at the desired temperature, by
prohibiting the path dimensions adjusted by the adjustment means of
the heating pathway and the cooling pathway from reaching zero.
[0040] Note that means 14 may be provided with heating side
temperature detecting means that detects that temperature upstream
from the adjustment means along the heating pathway, and cooling
side temperature detecting means that detects that temperature
upstream from the adjustment means along the cooling pathway. In
this case, the effect of the temperature gradient on the detecting
means can be suitably inhibited by prohibiting the supply of fluid
from the heating pathway and the cooling pathway.
[0041] The above and other objects, features, and advantages of the
present invention will be apparent from the following description
when taken in conjunction with the accompanying drawings which
illustrate preferred embodiments of the present invention by way of
example.
BRIEF DESCRIPTION OF DRAWINGS
[0042] [FIG. 1] A drawing showing the overall construction of a
temperature control device according to a first embodiment.
[0043] [FIG. 2] A flowchart showing the process sequence of
feedback control according to the same embodiment.
[0044] [FIG. 3] A drawing showing a method of setting the
manipulating variable of a cooling valve, a bypass valve, and a
heating valve according to the same embodiment.
[0045] [FIG. 4] A time chart showing the change in temperature of a
controlled object. when temperature control is temporarily
performed only by feedback control in the same embodiment.
[0046] [FIG. 5] A flow chart showing the process sequence for
setting a target value in the same embodiment.
[0047] [FIG. 6] A flow chart showing the process sequence of open
loop control in the same embodiment.
[0048] [FIG. 7] A time chart showing the change in temperature of a
controlled object. when also using open loop control.
[0049] [FIG. 8] A drawing showing the overall construction of a
temperature control device according to a second embodiment.
[0050] [FIG. 9] A drawing showing a method of setting the
manipulating variable of a cooling valve, a bypass valve, and a
heating valve according to a third embodiment.
[0051] [FIG. 10] A flow chart showing the sequence of an open loop
control adjustment support process according to a fourth
embodiment.
[0052] [FIG. 11] A drawing showing the overall construction of a
temperature control device according to a modification of the
second embodiment.
[0053] [FIG. 12] A drawing showing the construction of a
conventional temperature control device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
[0054] A first embodiment of the temperature control device
according to the present invention will be described below with
reference to the drawings.
[0055] FIG. 1 shows the overall construction of the temperature
control device according to the present embodiment.
[0056] The illustrated temperature control device is employed in,
for example, processes/manufacturing steps in the bioengineering
field and the chemical engineering field, bioengineering/chemical
experimentation, semiconductor manufacturing processes,
manufacturing processes for precision machinery. The temperature
control device comprises a temperature adjustment plate 10. The
temperature adjustment plate 10 is a plate shaped member that is
capable of supporting a controlled object from below by mounting
the controlled object on top thereof, and exchanges heat energy
with the controlled object. More specifically, a pathway
(temperature adjustment unit 11) is provided in the interior of the
temperature adjustment plate 10, and has a non-compressible fluid
flowing therein that is drawn therein via a confluence unit 12
(preferably a liquid medium (liquid temperature medium) that
mediates the exchange of heat energy). The temperature of the
temperature adjustment plate 10 is adjusted by the temperature of
this fluid. Note that the controlled object is, for example, an
experimental chemical substance, a semiconductor wafer, precision
machinery.
[0057] The fluid that flows in the interior of the temperature
adjustment plate 10 flows into a tank 16 via an discharge pathway
14. The tank 16 stores the fluid and there is a gap in the upper
portion thereof in which a gas is injected. Thus, even though a
change in the volume of the fluid occurs due to a change in
temperature, this change will be absorbed due to the gas acting as
a compressible fluid. In this way, impedances to the flow of the
fluid due to a change in the volume of the fluid will be
avoided.
[0058] The fluid inside the storage tank 16 is drawn therein by a
pump 18, and is discharged to a branching unit 19. Here, the pump
18 is, for example, a diaphragm pump, a vortex pump, a cascade
pump. A cooling pathway 20, a bypass pathway 30, and a heating
pathway 40 are connected to the branching unit 19.
[0059] The cooling pathway 20 cools the fluid that flows therein
from the branching unit 19 and flows out from to the confluence
unit 12. A cooling unit 22 is provided on the cooling pathway 20 so
as to cover a portion thereof. The cooling unit 22 cools the fluid
that flows therein from the branching unit 19. More specifically, a
pathway is provided in the cooling unit 22 in which fluid cooled to
a predetermined temperature (for example, water, oil and
refrigerant) flows, and the fluid inside the cooling pathway 20
will be cooled by means of this fluid. The cooling pathway 20 winds
between the upstream end and the downstream end of the cooling unit
22, and thereby enlarges the volume inside the cooling pathway 20
inside the cooling unit 22. Note that instead of this winding
structure, the volume inside the cooling unit 22 may, for example,
be enlarged by enlarging the path dimensions only inside the
cooling unit 22.
[0060] A cooling valve 24 that continuously adjusts the path
dimensions inside the cooling pathway 20 is provided on the
downstream side of the cooling pathway 20. A cooling temperature
sensor 26 that detects the temperature of the fluid inside the
cooling pathway 20 is provided upstream from the cooling valve 24
along the cooling pathway 20, and a cooling flow meter 28 that
detects the mass flow rate or the volume flow rate of the fluid
inside the cooling pathway 20 is provided downstream from the
cooling valve 24.
[0061] Note that the path dimensions of the cooling pathway 20
downstream from the cooling unit 22 are preferably substantially
uniform.
[0062] In contrast, the bypass pathway 30 allows the fluid that
flows therein from the branching unit 19 to flow to the temperature
adjustment unit 11 as is via the confluence unit 12. A bypass valve
34 that continuously adjusts the path dimensions inside the bypass
pathway 30 is provided on the downstream side of the bypass pathway
30. A bypass temperature sensor 36 that detects the temperature of
the fluid inside the bypass pathway 30 is provided upstream from
the bypass valve 34 along the bypass pathway 30, and a bypass flow
meter 38 that detects the mass flow rate or the volume flow rate of
the fluid inside the bypass pathway 30 is provided downstream from
the bypass valve 34.
[0063] The heating pathway 40 heats the fluid that flows therein
from the branching unit 19 and flows out from to the confluence
unit 12. A heating unit 42 is provided on the heating pathway 40 so
as to cover a portion thereof. The heating unit 42 heats the fluid
that flows therein from the branching unit 19. More specifically, a
pathway is provided in the heating unit 42 in which fluid heated to
a predetermined temperature (for example, water, oil, and
refrigerant) flows, and the fluid inside the heating pathway 40
will be heated by means of this fluid. The heating pathway 40 winds
between the upstream end and the downstream end of the heating unit
42, and thereby enlarges the volume inside the heating pathway 40
inside the heating unit 42. Note that instead of this winding
structure, the volume inside the heating unit 42 may, for example,
be enlarged by enlarging the path dimensions only inside the
heating unit 42.
[0064] A heating valve 44 that continuously adjusts the path
dimensions inside the heating pathway 40 is provided on the
downstream side of the heating pathway 40. A heating temperature
sensor 46 that detects the temperature of the fluid inside the
heating pathway 40 is provided upstream from the heating valve 44
along the heating pathway 40, and a heating flow meter 48 that
detects the mass flow rate or the volume flow rate of the fluid
inside the heating pathway 40 is provided downstream from the
heating valve 44.
[0065] Note that the path dimensions of the heating pathway 40
downstream from the heating unit 42 are preferably substantially
uniform.
[0066] The cooling pathway 20, the bypass pathway 30, and the
heating pathway 40 are connected by the confluence unit 12
positioned downstream thereof. Here, it is preferable that the path
dimensions inside the confluence unit 12 and the path dimensions
between the confluence unit 12 and the temperature adjustment unit
11 are in a range that does not reduce the flow rate of the fluid,
and no larger than the path dimensions of the cooling pathway 20,
the bypass pathway 30, and the heating pathway 40. In other words,
it is preferable that the flow dimensions of the confluence unit
12, and between the confluence unit 12 and the temperature
adjustment unit 11, are, to the greatest degree possible, set such
that the flow rate of the fluid that flows out from the cooling
valve 24, the bypass valve 34, and the heating valve 44 is not
reduced, and such that an accumulation of fluid caused by that
volume can be inhibited.
[0067] A supply temperature sensor 51 that detects the temperature
of the fluid supplied to the temperature adjustment unit 11 is
provided between the confluence unit 12 and the temperature
adjustment unit 11. In other words, the supply temperature sensor
51 detects the temperature of the fluid inside and/or near the
temperature adjustment unit 11.
[0068] The control device 50 adjusts the temperature of the fluid
inside the temperature adjustment unit 11 by manipulating the
cooling valve 24, the bypass valve 34, and the heating valve 44 in
response to a desired value of the temperature of the controlled
object (desired temperature Tr), and thereby indirectly controls
the temperature of the controlled object on the temperature
adjustment plate 10. In this case, the control device 50 suitably
references the detected values of the cooling temperature sensor
26, the bypass temperature sensor 36, the heating temperature
sensor 46, the cooling flow rate meter 28, the bypass flow rate
meter 38, the heating flow rate meter 48, the supply temperature
sensor 51.
[0069] Note that the control device 50 comprises a driver unit for
driving the cooling valve 24, the bypass valve 34, and the heating
valve 44, and a calculation unit for calculating the manipulating
signals that are output by the driver unit based upon the detected
values of each detection means. The calculation unit may be
constructed with specialized hardware means, or may comprise a
microcomputer. Furthermore, the calculation unit may comprise a
general purpose personal computer and a program for calculating
these signals.
[0070] According to the temperature control device, the temperature
inside the temperature adjustment unit 11 can be quickly changed in
response to a change in desired temperature Tr. In other words, the
temperature inside the temperature adjustment unit 11 can be
quickly changed to a desired temperature by adjusting the flow rate
of the fluid from the cooling pathway 20, the bypass pathway 30,
and the heating pathway 40, even when the desired temperature Tr is
at any value within a range in which the temperature of the fluid
inside the cooling pathway 20 is at or below the desired
temperature Tr, and the temperature of the fluid inside the heating
pathway 40 is at or above the desired temperature Tr.
[0071] Furthermore, by providing the bypass pathway 30, the
temperature control device can also reduce energy consumption when
maintaining the temperature inside the temperature adjustment unit
11 at a predetermined value. This will be explained below.
[0072] For example, assume that the fluid circulating in the
temperature adjustment unit 11 is water, the temperature inside the
cooling pathway 20 is "10.degree. C.", the temperature inside the
heating pathway 40 is "70.degree. C.", and the flow rate of the
fluid that flows inside the temperature adjustment unit 11 is "20
L/min.". In addition, assume that the detected value Td of the
supply temperature sensor 51 is controlled to "40.degree. C." so
that a steady state is achieved, and the temperature of the fluid
discharged from the temperature adjustment unit 11 is raised to
"43.degree. C.". In this case, temperature control can be performed
by causing the fluid of the cooling pathway 20 and the bypass
pathway 30 to flow into the temperature adjustment unit 11, and not
using the fluid inside the heating pathway 40. The energy
consumption at this point will be considered.
[0073] Assuming that the flow rate of the fluid that flows from the
cooling pathway 20 to the temperature adjustment unit 11 is "Wa",
the following formula will be realized.
20(L/min.).times.40(.degree. C.)=10(.degree.
C.).times.Wa+43(.degree. C.).times.(20-Wa)
[0074] Because of this, Wa.apprxeq."1.8 L/min."
[0075] Thus, the energy consumption Qa consumed in the cooling unit
22 is as follows.
Qc = ( 43 - 10 ) .times. 1.8 .times. 60 ( sec . ) / ( 860 :
conversion coefficient ) . = 4.1 kw ##EQU00001##
[0076] In contrast, with a construction in which the bypass pathway
30 is not provided, the energy consumption Qa of the cooling unit
22 and the energy consumption Qc of the heating unit 42 will be as
follows.
Qa=(43-10).times.10(L/min.).times.60(sec.)/860.apprxeq.23 kW
Qc=(70-43).times.10(L/min.).times.60(sec.)/860.apprxeq.19 kW
[0077] Thus, the energy consumption Q is "42 kW", and will be
approximately "10" times that when the bypass pathway 30 is
provided.
[0078] Next, the temperature control performed by the control
device 50 according to the present embodiment will be described in
detail. FIG. 2 shows the process sequence of feedback control from
amongst the processes performed by the control device 50. These
processes will be repeatedly executed at, for example,
predetermined intervals by the control device 50.
[0079] In this series of processes, it will first be determined in
Step S10 whether or not it is time for open loop control. In this
step, it will be determined whether or not the conditions for
executing feedback control have been created. Open loop control
will be performed under the conditions described later, and during
this time feedback control will not be performed.
[0080] In the event that a negative determination occurs in Step
S10, the detected value Td of the supply temperature sensor 51 will
be acquired in Step S12. Next, in Step S14, a basic manipulating
variable MB for feedback controlling the detected value Td to a
target value Tt will be calculated. Here, the target value Tt is
established based upon the desired temperature Tr, and is assumed
to be the desired temperature Tr during feedback control. The basic
manipulating variable MB is calculated based upon the degree of
deviation of the detected value Td with respect to the target value
Tt. More specifically, in the present embodiment, the basic
manipulating variable MB will be calculated by means of a PID
(Proportional-Integral-Derivative) calculation of the difference
.DELTA. between the detected value Td and the target value Tt.
[0081] Next, in Step S16, the basic manipulating variable MB will
be converted to each manipulating variable (ratio of opening Va, Vb
and Vc) of the cooling valve 24, the bypass valve 34, and the
heating valve 44. Here, the relationship shown in FIG. 3 will be
employed. The ratio of opening Va of the cooling valve 24 will
monotonically decrease in accordance with an increase in the basic
manipulating variable MB when the basic manipulating variable MB is
less than zero, and will be "0" when the basic manipulating
variable MB is zero or more. This is a setting for causing the flow
rate of the cooling pathway 20 to increase as the detected value Td
grows higher than the target value Tt, and for not employing the
cooling pathway 20 when the detected value Td is equal to or lower
than the target value Tt. In addition, the ratio of valve opening
Vc of the heating valve 44 will monotonically increase in
accordance with an increase in the basic manipulating variable MB
when the basic manipulating variable MB is greater than zero, and
will be "0" when the basic manipulating variable MB is zero or
less. This is a setting for causing the flow rate of the heating
pathway 40 to increase as the detected value Td grows lower than
the target value Tt, and for not employing the heating pathway 40
when the detected value Td is equal to or higher than the target
value Tt. Furthermore, the ratio of opening of the bypass valve 34
will monotonically decrease in accordance with the basic
manipulating variable MB moving away from zero. Note that in FIG.
3, it is preferable that each ratio of valve opening is set such
that the total flow rate from the three pathways does not change
due to the value of the basic manipulating variable MB.
[0082] According to this setting, the manipulating variables of the
three valves, i.e., the cooling valve 24, the bypass valve 34, and
the heating valve 44, can be set based upon a basic manipulating
variable MB calculated by means of a single PID calculation of the
difference .DELTA. between the detected value Td and the target
value Tt.
[0083] When the process of Step S16 in FIG. 2 is complete, the
cooling valve 24, the bypass valve 34, and the heating valve 44
will be manipulated in Step S18. Note that in the event that a
negative determination occurs in Step S10, or the process of Step
S18 is complete, this series of processes will be temporarily
complete.
[0084] By employing feedback control as described above, the
detected value Td can be placed at the target value Tt with a high
degree of accuracy. However, in order to increase the
responsiveness of the detected value Td to a change in the target
value Tt by means of feedback control, a request to increase the
gain of the feedback control will occur, but when the gain is
increased, the amount of variation in the detected value Td above
and below the target value Tt will increase. Thus, with feedback
control, there will be a mutual trade-off between an increase in
responsiveness with respect to a change in the target value Tt and
a reduction in the amount of variation in the detected value Td.
Because of this, responsiveness will be sacrificed when the amount
of variation is reduced. FIG. 4 shows the detected value Td and the
change in temperature of the controlled object with respect to the
use of feedback control when changing the target value Tt.
[0085] As shown in FIG. 4, a response lag will be created until the
detected value Td reaches the target value Tt, and an additional
long period of time will be needed until the temperature of the
controlled object achieves the target value Tt. This is due to the
fact that in order to change the temperature of the controlled
object, the temperature of the temperature adjustment unit 11 must
be changed, the temperature of the temperature adjustment plate 10
must be changed via the exchange of heat energy between the
temperature adjustment plate 10 and the temperature adjustment unit
11, and the exchange of heat energy must occur between the
temperature adjustment plate 10 and the controlled object. Because
of this, setting the feedback control so as to reduce the amount of
variation in the detected value Td will make it difficult for the
temperature of the controlled object to quickly achieve the target
value Tt by means of feedback control. Accordingly, in the present
embodiment, open loop control will be employed in the event that
the desired temperature Tr is changed. Furthermore, in this case,
the target value Tt will temporarily change more than the change in
the desired temperature Tr.
[0086] FIG. 5 shows the process sequence for setting the target
value Tt during a transition according to the present embodiment.
These processes will be repeatedly executed at, for example,
predetermined intervals by the control device 50.
[0087] In this series of processes, it will first be determined in
Step S20 whether or not a bias control flag is on. Here, the bias
control flag is a flag that executes bias control for causing a
temporary large change in the target value Tt. In the event that
the bias control flag is off, the flow will move to Step S22. In
Step S22, it will be determined whether or not the absolute value
of the amount of change .DELTA.Tr in the desired temperature Tr is
equal to or greater than a threshold .alpha.. Here, the threshold a
serves to determine whether or not a state exists in which the
temperature of the controlled object cannot quickly achieve a
desired change by means of the feedback control shown in FIG. 2. In
the event that it is determined that the absolute value of the
amount of change .DELTA.Tr in the desired temperature Tr is equal
to or greater than the threshold .alpha., then in Step S24, the
bias control flag will be turned on, and a measurement of the bias
control time will begin.
[0088] In the event that the process of Step S24 is complete, or
when a positive determination occurs in Step S20, then in Step S26
it will be determined whether or not the amount of change .DELTA.Tr
is larger than zero. This process will determine whether or not a
request to increase the temperature has occurred. In the event that
it is determined that the amount of change .DELTA.Tr is larger than
zero, the flow will move to Step S28. In Step S28, the target value
Tt will be set to a value that is the temperature of the fluid
inside the heating pathway 40 minus a predetermined offset value
.beta.. Here, the closer the target value Tt is brought to the
temperature inside the heating pathway 40, the quicker the
temperature of the controlled object can be increased. However, in
the event that the target value Tt is higher than the temperature
inside the heating pathway 40, control can no longer be performed.
The temperature inside the heating pathway 40 can be varied by
circulating the fluid in the heating pathway 40. Because of this,
the target value Tt will be set lower by only the offset value
.beta. with respect to the temperature inside the heating pathway
40.
[0089] In contrast, in the event that it is determined in Step S26
that the amount of change .DELTA.Tr is equal to or greater than
zero, then in Step S30 the target value Tt will be set to a value
equal to the temperature of the fluid inside the cooling pathway 20
plus a predetermined offset value .gamma.. Here, the setting of the
offset value .gamma. has the same meaning as the setting of the
offset value .beta..
[0090] The setting of the target value Tt by the processes of Steps
S28 and S30 will be continued across a bias continuation time Tbi
(Step S32). When the bias continuation time Tbi has elapsed, the
target value Tt will be assumed to be the desired temperature Td in
Step S34. Furthermore, the bias control flag will be turned off and
the measurement manipulation for measuring the bias control time
will be completed. Note that in the event that the process of Step
S34 is complete, or a negative determination occurs in Steps S22
and S32, this series of processes will be temporarily complete.
[0091] FIG. 6 shows the sequence of processes for temperature
control during a transition according to the present embodiment.
This process will be repeatedly executed at, for example,
predetermined intervals by the control device 50.
[0092] In this series of processes, it will first be determined in
Step S40 whether or not an open loop control flag that indicates
that open loop control will be performed is on. In the event that
the open loop control flag is on, the flow will move to Step S42.
In Step S42, it will be determined whether or not the absolute
value of the amount of change .DELTA.Tr in the target value Tt is
equal to or greater than a threshold .epsilon.. In the event that
it is determined that the absolute value of the amount of change
.DELTA.Tr in the target value Tt is equal to or greater than the
threshold .epsilon., then in Step S44, the open loop control flag
that indicates that open loop control will be performed will be
turned on, and a measurement manipulation that measures the open
loop control time will begin.
[0093] In the event that the process of Step S44 is complete, or in
the event that a positive determination occurs in Step S40, the
flow will move to Step S46. In Step S46, it will be determined
whether or not the target value Tt is higher than the temperature
Tb of the fluid inside bypass pathway 30 detected by the bypass
temperature sensor 36. In this step it will be determined whether
the bypass pathway 30 and the heating pathway 40 will be used to
perform open loop control, or whether the bypass pathway 30 and the
cooling pathway 20 will be used to perform open loop control.
[0094] In the event that it is determined that the target
temperature Tt is higher than the temperature Tb of the fluid
inside the bypass pathway 30, the flow will move to Step S48. In
Step S48, the bypass pathway 30 and the heating pathway 40 will be
used to perform open loop control. In other words, if the target
temperature Tt is higher than the temperature Tb of the fluid
inside the bypass pathway 30, the bypass pathway 30 and the heating
pathway 40 will be used to perform open loop control because using
the cooling pathway 20 will only waste energy. More specifically,
the temperature Tc of the heating temperature sensor 46 and the
flow rate Fc of the heating flow rate meter 48, and the temperature
Tb of the bypass temperature sensor 36 and the flow rate Fb of the
bypass flow rate meter 38, will be used to manipulate the heating
valve 44 and the bypass valve 34 so that the temperature of the
fluid supplied to the temperature adjustment unit 11 will be the
target value Tt. In other words, the heating valve 44 and the
bypass valve 34 will be manipulated so as to achieve the following
formula.
Tt.times.(Fc+Fb)=Tc.times.Fc+Tb.times.Fb
[0095] In contrast, in the event that it is determined in Step S46
that the target temperature Tt is equal to or lower than the
temperature Tb of the fluid inside the bypass pathway 30, the flow
will move to Step S50. In Step S50, the bypass pathway 30 and the
cooling pathway 20 will be used to perform open loop control. In
other words, if the target temperature Tt is equal to or lower than
the temperature Tb of the fluid inside the bypass pathway 30, the
bypass pathway 30 and the cooling pathway 20 will be used to
perform open loop control because using the heating pathway 40 will
only waste energy. More specifically, the temperature Ta of the
cooling temperature sensor 26 and the flow rate Fa of the cooling
flow rate meter 28, and the temperature Tb of the bypass
temperature sensor 36 and the flow rate Fb of the bypass flow rate
meter 38, will be used to manipulate the cooling valve 24 and the
bypass valve 34 so that the temperature of the fluid supplied to
the temperature adjustment unit 11 will be the target value Tt. In
other words, the cooling valve 24 and the bypass valve 34 will be
manipulated so as to achieve the following formula.
Tt.times.(Fa+Fb)=Ta.times.Fa+Tb.times.Fb
[0096] When the processes of Steps S48 and S50 are complete, the
flow will move to Step S52. In Step S52, it will be determined
whether or not a predetermined time period Top has elapsed. Here,
the predetermined time period Top establishes the time period in
which open loop control will continue. In the present embodiment,
the predetermined time period Top is set to be a longer time period
than the bias continuation time period Tbi, in which the target
value Tt differs from the desired temperature Tr due to the process
shown in FIG. 5, so that feedback control does not proceed within
the bias continuation time period Tbi. In the event that it is
determined that the predetermined time period Top has elapsed, then
in Step S54, the open loop control flag will be turned off, and the
measurement manipulation that measures the open loop control time
period will be complete.
[0097] Note that in the event that the process of Step S54 is
complete, or a negative determination occurs in Steps S42 and S52,
this series of processes will be temporarily complete.
[0098] FIG. 7 shows a temperature control graph that uses the
processes of FIG. 6 and FIG. 5. As shown in FIG. 7, the temperature
of the controlled object can more quickly achieve the target value
Tt than as shown in FIG. 4.
[0099] According to the present embodiment described in detail
above, the following effects are obtained.
[0100] (1) The temperature control device of the present embodiment
comprises the heating pathway 40 that heats the fluid and
circulates the same in the temperature adjustment unit 11, a
cooling pathway 20 that cools the fluid and circulates the same in
the temperature adjustment unit 11, a bypass pathway 30 that
circulates the fluid in the temperature adjustment unit 11 but does
not pass the fluid through the heating pathway 40 and the cooling
pathway 20, and a heating valve 44, a cooling valve 24, and a
bypass valve 34 that adjust the path dimensions downstream of each
of the heating pathway 40, the cooling pathway 20, and the bypass
pathway 30. In this way, when the temperature of the controlled
object is to be controlled to a desired level, the temperature of
the controlled object can quickly achieve the desired level.
[0101] (2) The heating pathway 40 and the cooling pathway 20 share
the bypass pathway 30. In this way, a shared bypass pathway 30 can
be used when fluid is to be supplied from the heating pathway 40
and the bypass pathway 30 to the temperature adjustment unit 11,
and when fluid is to be supplied from the cooling pathway 20 and
the bypass pathway 30 to the temperature adjustment unit 11.
Because of this, compared to situations in which different bypass
pathways must be used, the structure of the temperature control
device can be simplified.
[0102] (3) The temperature control device of the present embodiment
further comprises the pump 18 that draws in the fluid of the
temperature adjustment unit 11 and discharges the same to the
heating pathway 40, the cooling pathway 20, and the bypass pathway
30. By arranging the pump 18 upstream from the heating pathway 40,
the cooling pathway 20, and the bypass pathway 30, the length of
the fluid pathway between the heating valve 44, the cooling valve
24, and the bypass valve 34 and the temperature adjustment unit 11
can be shortened compared to when arranged downstream from the
heating pathway 40, the cooling pathway 20, and the bypass pathway
30 and upstream from the temperature adjustment unit 11. Because of
this, the fluid supplied from the heating valve 44, the cooling
valve 24, and the bypass valve 34 can be quickly delivered to the
temperature adjustment unit 11, and the temperature of the
temperature adjustment unit 11 can quickly achieve the desired
temperature.
[0103] (4) With the temperature control device of the present
embodiment, the tank 16 that stores the fluid is provided upstream
from the heating pathway 40, the cooling pathway 20, and the bypass
pathway 30 and downstream from the temperature adjustment unit 11,
and a gas is filled into the upper portion of the tank 16. In this
way, changes in the volume of the fluid caused by a change in
temperature can be absorbed, and the circulation of the fluid can
be suitably maintained regardless of the change in volume of the
fluid due to temperature.
[0104] (5) The detected value Td is feedback controlled to the
target value Tt by means of the supply temperature sensor 51 that
detects the temperature of the fluid inside and/or near the
temperature adjustment unit 11. In this way, the detected value Td
can achieve the target value Tt with a high degree of accuracy.
[0105] (6) During feedback control, the basic manipulating variable
MB that is based upon the degree of deviation of the detected value
Td from the target value Tt was converted manipulating variable of
the path dimension (ratio of opening Va, Vb and Vc) of each of the
heating pathway 40, the cooling pathway 20, and the bypass pathway
30. In this way, the path dimensions of the three pathways can be
adjusted (manipulated) based upon the single basic manipulating
variable MB.
[0106] (7) Instead of performing feedback control over a
predetermined time period after the target value Tt changes, the
temperature of the fluid inside and/or near the temperature
adjustment unit 11 is open loop controlled based upon the detected
value of the bypass temperature sensor 36 that detects the
temperature of the bypass pathway 30. In this way, the
responsiveness during the change in the target value Tt can be
increased, even if the feedback control is set so as to inhibit the
amount of variation in the detected value Td above and below the
target value Tt.
[0107] (8) When the target value Tt is changed, the temperature of
the temperature adjustment unit 11 is open loop controlled to the
target value Tt by manipulating the path dimensions of the bypass
pathway 30 and the cooling pathway 20 when the temperature of the
fluid inside the bypass pathway 30 is higher than the target value
Tt, and the temperature of the temperature adjustment unit 11 is
open loop controlled to the target value Tt by manipulating the
path dimensions of the bypass pathway 30 and the heating pathway 40
when the temperature of the fluid inside the bypass pathway 30 is
lower than the target value Tt. In this way, energy consumption can
be reduced to the greatest degree possible while performing open
loop control.
[0108] (9) When a requirement relating to the temperature of the
temperature adjustment unit 11 is changed, the target value Tt is
changed to be larger than the change of the requirement. In this
way, the temperature of the temperature adjustment unit 11 and the
controlled object can be all the more quickly changed to the
desired temperature.
Second Embodiment
[0109] A second embodiment will be described below with reference
to the drawings that are focused on the points that differ from the
first embodiment.
[0110] FIG. 8 shows the overall construction of the temperature
control device according to the present embodiment. As shown in
FIG. 8, in the present embodiment, a effusion pathway 60 that
effuses the fluid inside the cooling pathway 20 to the discharge
pathway 14 is connected between the cooling temperature sensor 26
and the cooling valve 24 along the cooling pathway 20. In addition,
a effusion pathway 62 that effuses the fluid inside the heating
pathway 40 to the discharge pathway 14 is connected between the
heating temperature sensor 46 and the heating valve 44 along the
heating pathway 40.
[0111] These effusion pathways 60 and 62 are sufficiently smaller
than the path dimensions of either of the cooling pathway 20 and
the heating pathway 40. This is in order to allow a minute amount
of fluid to be effused from the cooling pathway 20 and the heating
pathway 40 to the discharge pathway 14 when the cooling valve 24
and the heating valve 44 are closed.
[0112] In other words, when the supply of fluid from the heating
pathway 40 and the cooling pathway 20 to the temperature adjustment
unit 11 is prohibited, a temperature gradient will be created
between the downstream side of the heating valve 44 and the cooling
valve 24 and the prohibited pathway. Thus, due to the effects of
the temperature gradient on the temperature of the fluid to be
supplied to the temperature adjustment unit 11 immediately after
the prohibition is eliminated, a longer period of time may be
needed for the temperature of the temperature adjustment unit 11 to
achieve the desired temperature. In addition, in this case, because
the temperatures of the cooling temperature sensor 26 and the
heating temperature sensor 46 will be affected by this temperature
gradient, they will detect temperatures separated from the
temperature near the cooling unit 22 and the temperature near the
heating unit 42. Because of this, the ability to control the open
loop control when the target value Tt is changed may also
decline.
[0113] In contrast to this, by providing the effusion pathways 60
and 62 in the present embodiment, temperature gradients upstream
from the effusion pathways 60 and 62 can be suitably inhibited when
the heating valve 44 and the cooling valve 24 are in the closed
state, and the temperature of the temperature adjustment unit 11
can more quickly achieve the desired temperature.
[0114] According to the present embodiment described above, the
following effect will be obtained in addition to the effects (1) to
(9) of the first embodiment.
[0115] (10) The effusion pathways 60 and 62 are provided upstream
from the heating valve 44 along the heating pathway 40 and upstream
from the cooling valve along the cooling pathway. In this way,
temperature control when the target value Tt is changed can be more
suitably performed.
Third Embodiment
[0116] A third embodiment will be described below with reference to
the drawings that are focused on the points that differ from the
first embodiment.
[0117] FIG. 9 shows the relationship between the basic manipulating
variable MB according to the present embodiment and the ratio of
opening Va, Vb and Vc of the cooling valve 24, the bypass valve 34,
and the heating valve 44. As shown in FIG. 9, in the present
embodiment, the ratio of opening Va of the cooling valve 24 and the
ratio of opening Vc of the heating valve 44 are set so as not to be
in a completely closed state. In other words, the ratio of opening
Va of the cooling valve 24 will monotonically decrease in
accordance with an increase in the basic manipulating variable MB
when the basic manipulating variable MB is less than zero, and will
be at the minimum ratio (>0) when the basic manipulating
variable MB is zero or more. In addition, the ratio of opening Vc
of the heating valve 44 will monotonically increase in accordance
with an increase in the basic manipulating variable MB when the
basic manipulating variable MB is greater than zero, and will be at
a minimum ratio (>0) when the basic manipulating variable MB is
zero or less.
[0118] In this way, without providing the effusion pathways 60 and
62 shown in FIG. 8, when the supply of the fluid from the bypass
pathway 30 becomes the main supply route and the temperature
control inside the temperature adjustment unit 11 is stable,
temperature gradients upstream of the cooling valve 24 and the
heating valve 44 can be inhibited.
[0119] According to the present embodiment described above, the
following effect will be obtained in addition to the effects (1) to
(9) of the first embodiment.
[0120] (11) The ratio of opening Va of the cooling valve 24 and the
ratio of opening Vc of the heating valve 44 are set so as not to be
continuously in a completely closed state. In this way, temperature
gradients upstream of the cooling valve 24 and the heating valve 44
can be inhibited, and the temperature of the temperature adjustment
unit 11 can more quickly achieve the desired temperature.
Fourth Embodiment
[0121] A fourth embodiment will be described below with reference
to the drawings that are focused on the points that differ from the
first embodiment.
[0122] In the first embodiment, the temperature of the controlled
object was quickly brought to the desired value by performing open
loop control of the temperature near the temperature adjustment
unit 11 when the target value Tt changes. The optimal value of the
control gain of the open loop control, the bias continuation time
period Tbi, and the predetermined interval Top in which open loop
control continues will depend upon the temperature plate 10 and the
controlled object, and can be changed. On the other hand, each time
a user changes the controlled object, manually changing these
parameters requires a great deal of work in order to adjust them.
Accordingly, in the present embodiment, an adjustment support
function is installed in the control device 50. FIG. 10 shows the
process sequence of the adjustment support according to the present
embodiment. This process will be repeatedly executed at, for
example, predetermined intervals by the control device 50.
[0123] In this series of processes, it will first be determined in
Step S70 whether or not there is a mode that performs adjustment of
open loop control (test mode). Here, the presence or absence of the
test mode may be determined by providing a function in, for
example, the manipulating unit of the control device 50, for a user
to request the test mode. In the event that it is determined that
the test mode is present, then in Step S72, suggested bias
continuation time periods Tbi will be displayed to the user on a
viewable display means. Here, the suggested bias continuation time
periods Tbi are preset in a range of suitable values for the
presumed controlled object.
[0124] Next, in Step S74, it will be determined whether or not the
input of a bias continuation time period Tbi has occurred. In this
step it will be determined whether or not the user has selected one
of the suggested bias continuation time periods Tbi. In the event
that it is determined that the user has selected a specific
suggestion (Step S74: YES), then in Step S76, the selected
suggestion will be used to begin temperature control. If the
temperature control is complete, then in Step S78, the viewer will
be notified via the viewable display means whether or not the bias
continuation time period Tbi has been set. In the event that a
declaration of intent is input from the user indicating that it
will not be set (Step S80: NO), the processes of Steps S72-S78 will
be repeated.
[0125] In contrast, in the event that a command is input indicating
that one of the suggestions has been selected by the user and that
the bias continuation time Tbi has been set (Step S80: YES), the
bias continuation time period Tbi will be stored in Step S82. Note
that in the event that the process of Step S82 is complete, or a
negative determination occurs in Steps S70, this series of
processes will be temporarily complete.
[0126] According to the present embodiment described above, the
following effect will be obtained in addition to the effects (1) to
(9) of the first embodiment.
[0127] (12) An open loop control adjustment support function was
provided that prompts a user to select any one of a plurality of
selections relating to the bias continuation time period Tbi, and
performs temperature control in accordance with the selected value.
In this way, the burden on a user of the temperature control device
when adjusting open loop control in accordance with the controlled
object can be reduced.
Other Embodiments
[0128] Note that each of the aforementioned embodiments can be
modified as follows. [0129] The changes from the first embodiment
applied to the fourth embodiment may also be applied to the second
and third embodiments. [0130] In the fourth embodiment, the
adjustment parameter used when performing adjustment support of
open loop control was the bias continuation time period Tbi, but
the present invention is not limited thereto. For example, the
continuation time period of open loop control (predetermined
interval Top) may be the adjustment parameter. In addition, the
setting of the target value in the bias control shown in FIG. 5
(offset values .beta., .gamma.) may, for example, be the adjustment
parameter. Furthermore, a plurality of these parameters may be the
adjustment parameters. [0131] In the fourth embodiment, the user
was supported so as to be able to select a suitable parameter in
accordance with the controlled object, but the present invention is
not limited thereto. For example, a process may be performed such
that when initializing each of the parameters arbitrarily, i.e.,
the bias continuation time period Tbi, the predetermined interval
Top, and the offset values .beta., .gamma., in order to perform
temperature control, the temperature of the controlled object (or
the temperature of the temperature adjustment plate 10) will be
monitored, and in the event that the time lag needed to bring the
temperature to the target value is not within an allowable range,
at least one of the parameters will be automatically changed. In
this way, the burden on the user can be lightened because the open
loop control can be automatically adjusted so that the time lag
needed to bring the temperature to the target value will be within
an allowable range. [0132] The method in which the basic
manipulating variable MB is converted to the manipulating variables
of the cooling valve 24, the bypass valve 34, and the heating valve
44 is not limited to that shown in FIGS. 3 and 9. In FIGS. 3 and 9,
any two of the manipulating variables of the cooling valve 24,
bypass valve 34 and the heating valve 44 are changed in response to
a change in the temperature difference .DELTA. between target value
Tt and detected value Td. However, the present invention is not
limited thereto, and for example, all the manipulating variables
may be changed. In addition, in FIGS. 3 and 9, each of the
manipulating variables of the cooling valve 24, the bypass valve
34, and the heating valve 44 are a zero order function or a first
order function of the temperature difference .DELTA., but the
present invention is not limited thereto. [0133] In the third
embodiment, the cooling valve 24 and the heating valve 44 are
prohibited from being placed in the closed state regardless of the
value of the basic manipulating variable MB, however the present
invention is not limited thereto. The cooling valve 24 and the
heating valve 44 may be prohibited from being placed in the closed
state only when the basic manipulating variable MB is near zero. In
other words, because it is assumed that the detected value Td
tracks the target value Tt and the detected value Td is in the
steady state prior to the change of the desired temperature Tr.
Only in this situation, the cooling valve 24 and the heating valve
44 may be prohibited from being placed in the fully closed state
only when the basic manipulating variable MB is near zero so as to
provide for a change in the target value Tt. Note that in this
case, it is preferable that the amount of change in the
manipulating variable of the cooling valve 24 be larger than the
amount of change in the manipulating variable of the heating valve
44 when the basic manipulating variable MB is smaller than zero,
and the amount of change in the manipulating variable of the
heating valve 44 be smaller than the amount of change in the
manipulating variable of the cooling valve 24 when the basic
manipulating variable MB is larger than zero. [0134] The effusion
pathways 60 and 62 are not limited to those illustrated in the
second embodiment (FIG. 8). For example, as shown in FIG. 11, the
temperature control device may comprise a effusion pathway 60 that
bypasses the cooling valve 24 and is connected to the upstream and
downstream sides of the cooling valve 24 along the cooling pathway
20, and a effusion pathway 62 that bypasses the heating valve 44
and is connected to the upstream and downstream sides of the
heating valve 44 along the heating pathway 20. Note that here as
well, it is preferable that the effusion pathways 60 is downstream
from the cooling temperature meter 26 and the effusion pathways 62
is downstream from the heating temperature meter 46. [0135] In each
of the aforementioned embodiments, the predetermined interval Top
and the bias continuation time period Tbi in which open loop
control will continue may be set independently, but they may be
corresponding with each other. [0136] Feedback control is not
limited to PID control. For example, PI control or I control is
also possible. Here, for example, as with each of the
aforementioned embodiments, in a construction that performs open
loop control during a transition in which the target value is
changed, the goal of feedback control is matching the detected
value Td with the target value Tt with a high degree of accuracy
during normal times, and reducing variation in the detected value
Td as much as possible. Because of this, performing feedback
control on the detected value Td in order to achieve the target
value Tt based upon the cumulative value of amounts indicating the
degree of deviation between the detected value Td and the target
value Tt as integral control is particularly effective. [0137] Open
loop control is not limited to that illustrated in the
aforementioned embodiments. For example, when the temperature of
the fluid inside the bypass pathway 30 is higher than the target
value Tt, the ratio of opening of the cooling valve 24 and the
bypass valve 30 will be set with reference to the ratio shown in
FIG. 3, and when the temperature of the fluid inside the bypass
pathway 30 is lower than the target value Tt, the ratio of opening
of the heating valve 44 and the bypass valve 30 will be set with
reference to the ratio shown in FIG. 3. Here, open loop control can
be performed by calculating the opening ratio of two valves so that
the target value Tt can be achieved in response to the temperature
of the fluid inside the pathway being used. According to this
method in particular, the use of a flow meter can be avoided.
Because a flow meter is immersed in fluid, it is difficult to
expect it to be reliable over a long period of use across the
entire temperature range between the temperature of the fluid
inside the heating pathway 40 and the temperature of the fluid
inside the cooling pathway 20, and thus it is preferable to simply
perform open loop control instead of using a flow meter. Note that
when, for example, the temperature of the fluid inside the bypass
pathway 30 is higher than the target value Tt, the ratios of
opening of the cooling valve 24 and the bypass valve 30 may be set
in accordance with the ratio between the difference of the fluid
temperature inside the cooling pathway 20 with respect to the
target value Tt, and the difference of the target value Tt with
respect to the fluid temperature inside the bypass pathway 30,
without using the opening ratio shown in FIG. 3. Likewise, when the
temperature of the fluid inside the bypass pathway 30 is lower than
the target temperature Tt, the ratios of opening of the heating
valve 44 and the bypass valve 30 may be set in accordance with the
ratio between the difference of the fluid temperature inside the
bypass pathway 30 with respect to the target value Tt, and the
difference of the target value Tt with respect to the fluid
temperature inside the heating pathway 40. [0138] Without limiting
the use of feedback control, only the open loop control illustrated
in Steps S48 and S50 of FIG. 6 may be performed. In addition,
regardless of the presence or absence of a change in the target
value, the final basic manipulating variable MB may be calculated
by revising the basic manipulating variable determined by the open
loop control illustrated in S48 and S50 with feedback control. In
addition, conversely, regardless of the presence or absence of a
change in the target value, only feedback control may be performed.
Even in this case, when the desired temperature Td is changed, the
aforementioned bias control is effective to cause a larger change
in the target value Tt than the desired temperature Td With
feedback control, there is a mutual trade-off between reducing the
response lag and reducing variations in the detected value Td with
respect to the target value Tt. However, because the response lag
can be reduced regardless of feedback control gain by performing
bias control, the variations can be reduced while reducing the
response lag. [0139] The feedback control is not limited to being
performed by converting the desired amount of feedback control (the
basic manipulating variable MB) to the manipulating variables of
the cooling valve 24, the bypass valve 34, and the heating valve
44. For example, the manipulating variables of the cooling valve
24, the bypass valve 34, and the heating valve 44 may each be
independently set based upon the degree of deviation between the
target value Tt and the detected value Td. However, even in this
case, it is preferable that only the manipulating variables of the
bypass valve 34 and the cooling valve 24 be targeted for change
when the target value Tt is higher than the detected value Td, and
only the manipulating variables of the bypass valve 34 and the
heating valve 44 be targeted for change when the target value Tt is
lower than the detected value Td. [0140] A storage means having a
function that absorbs a change in the volume of the fluid due to
temperature is not limited to that illustrated in each of the
aforementioned embodiments, in which the entire tank 16 is not
filled with fluid, and has a space filled with a gas. For example,
a construction is possible in which the tank 16 is filled with
fluid and has no gap, and the volume of the tank 16 is changed in
response to a force applied by the fluid to the inner wall of the
tank 16. [0141] In each of the aforementioned embodiments, the
adjustment means that adjust the flow ratio of the fluid supplied
from the cooling pathway 20, the bypass pathway 30, and the heating
pathway 40 to the temperature adjustment plate 10 employed the
cooling valve 24, the bypass valve 34, and the heating valve 44.
However, the present invention is not limited thereto. For example,
it is possible to provide a plurality of each of these pathways,
provide a valve on each of these that manipulates by fully opening
and fully closing, and set the number of pathways that supply fluid
to the temperature adjustment plate 10 as the manipulating
variable. Furthermore, a plurality of pathways may be prepared, and
manipulations may be performed to connect each of the pathways to
anywhere downstream of the cooling unit 22, the heating unit 42,
and the pump 18. In addition, a pump may be provided on each of the
cooling pathway 20, the bypass pathway 30, and the heating pathway
40, and the flow ratio may be adjusted by individually manipulating
the discharge capabilities thereof. [0142] Moreover, the
temperature adjustment plate 10 is not limited to a thin
rectangular plate member, and may be a thin cylindrical plate
member. Furthermore, the temperature adjustment unit 11 is not
limited to be provided in an internal plate member capable of
supporting a controlled object from directly below, and may for
example directly contact a plurality of side surfaces of the
controlled object to control the temperature thereof.
* * * * *