Patent Application
20100116484
The present application claims priority based on Japan Patent Application No. 2008-289465 filed on Nov. 12, 2008, and the entire contents of that application is incorporated by reference in this specification.
The present invention relates to a temperature control device that controls the temperature of a controlled object at a desired level by circulating a fluid in a temperature adjustment unit arranged in the vicinity of the controlled object.
With this type of construction, the temperature of a 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.
Note that a conventional temperature control device may be one other than that shown in
[Patent Reference 1] Japanese Published Patent Application No. 2000-89832.
The aforementioned temperature control device requires a long period of time in order to change the desired temperature of a controlled object. In other words, 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.
The present invention solves the aforementioned problem, and an object thereof is to provide a temperature control device that can, when controlling the temperature of a controlled object at a desired level by circulating a fluid in a temperature adjustment unit arranged in the vicinity of the controlled object, quickly achieve the desired temperature of the controlled object.
A first aspect of the invention is a temperature control device that controls the temperature of a controlled object at a desired temperature by circulating a fluid in a temperature adjustment unit arranged in the vicinity of 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 circulates the fluid in the temperature adjustment unit without passing the fluid through the heating pathway and the cooling pathway, an adjustment means that adjusts a flow ratio of the fluid that is supplied from the heating pathway, cooling pathway, and bypass pathway to the temperature adjustment unit, and a flow means that flows the fluid in order to circulate the fluid, and wherein a heating unit for heating the fluid is arranged in the heating pathway, and the flow means is disposed downstream from the heating unit along at least one of the pathways for circulating the fluid.
With the first aspect of the invention, the temperature of the fluid supplied to the temperature adjustment unit can be quickly changed by adjusting the flow ratio of the fluid supplied to the temperature adjustment unit via the heating pathway, the cooling pathway, and the bypass pathway. Furthermore, because the flow means is arranged downstream from the heating unit, an increase in pressure on the portion of the heating pathway heated by the heating unit due to the suction force applied to the fluid by the flow means can also be inhibited. Because of this, the withstand pressure needed for the heated portion can also be reduced. Note that the path dimensions of a confluence unit that combines the flows of the heating pathway, the cooling pathway, and the bypass pathway may be less than or equal to the total of the path dimensions of the pathways upstream thereof, or may be less than the total thereof.
A second aspect of the invention is the temperature control device according to the first aspect, wherein the adjustment means comprises a flow adjustment means to adjust the flow of the fluid supplied from the heating pathway to the temperature adjustment unit, wherein the flow adjustment means is arranged upstream from the heating unit.
In the second aspect of the invention, by arranging the flow adjustment means to adjust the flow of fluid supplied from the heating pathway to the temperature adjustment unit upstream from the heating unit, hindrance by the adjustment means on the effects of the flow means in reducing the pressure on the portion of the heating pathway heated by the heating unit can be suitably avoided.
A third aspect of the invention is the temperature control device according to the first aspect of the second aspect, wherein at least one of the pathways for circulating the fluid comprises a volume change absorption means which functions to absorb a change in the volume of the fluid due to temperature.
When the volume of the fluid is temperature dependant, 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 the third aspect of the invention comprises volume change absorption means, the circulation of the fluid can be suitably maintained when the volume of the fluid changes.
Note that the volume change absorption means is preferably arranged upstream of the flow means.
A fourth aspect of the invention is the temperature control device according to any of the 1st to 3rd aspects, wherein a discharge pathway that diverts the fluid from the adjustment means and discharges the fluid from the upstream side to the downstream side thereof is arranged in the heating pathway and the cooling pathway.
When the discharge of fluid from the heating pathway and the cooling pathway to the temperature adjustment unit is prohibited, a temperature gradient will be created in these pathways. Thus, immediately after the prohibition is eliminated, due to the effect of the temperature gradient in the fluid to be discharged to the temperature adjustment unit, a longer period of time may be needed for the temperature of the temperature adjustment unit to achieve the desired temperature. By including the discharge pathway in the fourth aspect of the invention, temperature gradients in the heating pathway and the cooling pathway can be suitably inhibited, and the temperature of the temperature adjustment unit can quickly achieve the desired temperature.
Note that in the fourth aspect of the invention, heating side temperature detecting means may be arranged in the heating pathway, and cooling side temperature detecting means may be arranged in the cooling pathway. In this case, by providing the discharge pathway, the effect of the temperature gradient on the detecting means caused by prohibiting the discharge of fluid from the heating pathway and the cooling pathway can be suitably inhibited.
A fifth aspect of the invention is the temperature control device according to any of the 1st to 4th aspects, wherein a bypass pathway employed when fluid is supplied from both the heating pathway and the bypass pathway to the temperature adjustment unit, and a bypass pathway employed when fluid is supplied from both the cooling pathway and the bypass pathway to the temperature adjustment unit, include a shared pathway.
In the fifth aspect of the invention, a shared bypass pathway can be employed 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 separate bypass pathways must be used, the structure of the temperature control device can be simplified.
A sixth aspect of the invention is the temperature control device according to the 1st to 5th aspect, further comprising manipulating means that serves to manipulate the adjustment means so as to control the temperature of the fluid inside and/or near the temperature adjustment unit to a target level.
In the sixth aspect of the invention, the temperature of the temperature adjustment unit can be adjusted to a desired level by providing the manipulating means.
A seventh aspect of the invention is the temperature control device according to the 6th aspect, further comprising a supply temperature detection means that detects the temperature of the fluid inside and/or near the temperature adjustment unit, and wherein the manipulating means feedback controls the value detected by the supply temperature detection means to a target value.
In the seventh aspect of the invention, the detected value can be adjusted to the target value with a high degree of accuracy because the manipulating means performs feedback control.
A eighth aspect of the invention is the temperature control device according to the 7th aspect, wherein the adjustment means is a means that 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 a path dimension manipulating variable for each of the heating pathway, the cooling pathway, and the bypass pathway.
In the eighth aspect of the invention, only by quantifying the degree of deviation of the detected value from the target value with a single amount, the path dimensions of the three pathways can be adjusted (manipulated) based on this quantified amount.
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 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 degree of deviation when the detected value is smaller than the target value.
A ninth aspect of the invention is the temperature control device according to the 7th or 8th aspect, further comprising a bypass temperature detecting means that detects the temperature of the bypass pathway, wherein instead of feedback control, the manipulating means, for a predetermined period of time after a change in the target value, manipulates the adjustment means so as to open loop control the temperature of the fluid inside and/or near the temperature adjustment unit based upon the detected value of the bypass temperature detecting means.
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. Then, when the gain of the control increases, the amount of variation in which the detected value varies above and below the target value will increase. Thus, with feedback control, there is a mutual trade-off between an increase in responsiveness and inhibition of the amount of variation. In the ninth aspect of the invention, 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.
A tenth aspect of the invention is the temperature control device according to the 9th aspect, wherein when the temperature of the fluid inside the bypass pathway is higher than the target value, the open loop control is performed by controlling the flow ratio of fluid supplied from the bypass pathway and the cooling pathway to the temperature adjustment unit for the predetermined period of time, and when the temperature of the fluid inside the bypass pathway is lower than the target value, the open loop control is performed by controlling the flow ratio of fluid supplied from the bypass pathway and the heating pathway to the temperature adjustment unit for the predetermined period of time.
In the tenth aspect of the invention, the amount of energy consumption can be reduced, 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, the amount of energy consumption can be reduced, 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.
A eleventh aspect of the invention is the temperature control device according to the 6th to 10th aspects, further comprising a transient target value setting means that changes the target value, when changing the requested temperature of the temperature adjustment unit, so as to be larger than the change of the requested change.
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 changing the temperature of the temperature adjustment unit, and thus the response lag in the change in temperature of the controlled object will become all the more prominent. Here, with the eleventh aspect of the invention, when an actual request is to be changed, the temperature of the temperature adjustment unit and the controlled object can be quickly changed to the requested temperature by making the change in the target value larger than the requested change.
A twelfth aspect of the invention is the temperature control device according to any of the 9th to 11th aspects, further comprising an open loop control adjustment support means that outputs a prompt signal 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 setting of the target value during open loop control, and performs temperature control in accordance with the selected value.
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 optimally performed on the controlled object. By providing the adjustment support means in the twelfth aspect of the invention, the amount of work performed when a user of the temperature control device applies these parameters in response to the controlled object can be reduced.
A thirteenth aspect of the invention is the temperature control device according to any of the 6th to 12th aspects, wherein the manipulating means prevents the flow of the fluid adjusted by the adjustment means from reaching zero in the heating pathway and the cooling pathway when the temperature of the temperature adjustment unit is in a steady state.
When the discharge of fluid from the heating pathway and the cooling pathway to the temperature adjustment unit is prohibited, a temperature gradient will be created on the downstream side of the adjustment means. Thus, due to the effects of the temperature gradient in the fluid to be discharged 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. With the thirteenth aspect of the invention, when the temperature of the temperature adjustment unit is in a steady state, temperature gradients can be suitably inhibited, and the temperature of the temperature adjustment unit can more quickly achieve the desired temperature, by prohibiting the flow adjusted by the adjustment means of the heating pathway and the cooling pathway to reach zero.
Note that the thirteenth aspect of the invention may be provided with heating side temperature detecting means upstream from the adjustment means along the heating pathway, and cooling side temperature detecting means 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 discharge of fluid from the heating pathway and the cooling pathway.
A fourteenth aspect of the invention is a temperature control device that controls the temperature of a controlled object at a desired level by circulating a fluid in a temperature adjustment unit arranged in the vicinity of the controlled object. The temperature control device comprises a heating pathway that heats the fluid and circulates the fluid in the temperature adjustment unit, a cooling pathway that cools the fluid and circulates the fluid in the temperature adjustment unit, a bypass pathway that circulates the fluid in the temperature adjustment unit without passing the fluid through the heating pathway and cooling pathway, and an adjustment means that adjusts the flow ratio of the fluid that is supplied from the heating pathway, cooling pathway, and bypass pathway to the temperature adjustment unit.
With the fourteenth aspect of the invention, the temperature of the fluid supplied to the temperature adjustment unit can be quickly changed by adjusting the flow ratio of the fluid supplied to the temperature adjustment unit via the heating pathway, the cooling pathway, and the bypass pathway. Note that the fourteenth aspect of the invention may further include at least one of the matters to define the invention in the 2nd to 13th aspects. In addition, the path dimensions of a confluence unit that combines the flows of the heating pathway, the cooling pathway, and the bypass pathway may be less than or equal to the total of the path dimensions of the pathways upstream thereof, or may be less than the total thereof.
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.
A first embodiment of the temperature control device according to the present invention will be described below with reference to the drawings.
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, and manufacturing processes for precision machinery such as semiconductor devices, etc. The temperature control device comprises a temperature adjustment plate 10. The temperature adjustment plate 10 exchanges heat energy with a controlled object by supporting a controlled object placed thereon. 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 (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 object that is to be manufactured into precision machinery.
The fluid that flows in the interior of the temperature adjustment plate 10 is supplied to a branching unit 18 via a return pathway 16. A cooling pathway 20, a bypass pathway 30, and a heating pathway 40 are connected to the branching unit 18.
The cooling pathway 20 is a pathway for cooling the fluid that flows therein from the branching unit 18 and causing the fluid to flow out therefrom 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 18. More specifically, a pathway is provided in the cooling unit 22 in which fluid cooled to a predetermined temperature (water, oil, refrigerant, etc.) flows, and this fluid will cool the fluid inside the cooling pathway 20. The cooling pathway 20 winds between the upstream end and the downstream end of the cooling unit 22, and thereby enlarges the volume of the cooling pathway 20 inside the cooling unit 22. Note that instead of this winding structure, the volume of the cooling pathway 20 inside the cooling unit 22 may, for example, be enlarged by enlarging the path dimensions only inside the cooling unit 22. In addition, the terms “upstream” and “downstream” above are references for the direction in which the fluid flows, and respectively mean rearward and forward of the direction of flow.
In addition, a cooling valve 24 that continuously adjusts the path dimensions inside the cooling pathway 20 is provided on the upstream side of the cooling unit 22 along the cooling pathway 20. In addition, a cooling temperature sensor 26 that detects the temperature of the fluid inside the cooling pathway 20, and a cooling flow meter 28 that detects the mass flow or the volume flow of the fluid inside the cooling pathway 20, are provided downstream from the cooling unit 22 along the cooling pathway 20.
Note that the path dimensions of the cooling pathway 20 downstream from the cooling unit 22 are preferably substantially uniform.
In contrast, the bypass pathway 30 causes the fluid that flows from the branching unit 18 to be discharged as is to the temperature adjustment unit 11 via the confluence unit 12. A bypass valve 34 that continuously adjusts the path dimensions inside the bypass pathway 30 is provided on the upstream side of the bypass pathway 30. A bypass temperature sensor 36 that detects the temperature of the fluid inside the bypass pathway, and a bypass flow meter 38 that detects the mass flow or the volume flow of the fluid inside the bypass pathway 30, are provided downstream from the bypass valve 34 along the bypass pathway 30.
The heating pathway 40 heats the fluid that flows therein from the branching unit 18 and flows out therefrom 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 18. 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.
A heating valve 44 that continuously adjusts the path dimensions inside the heating pathway 40 is provided upstream of the heating unit 42 along the heating pathway 40. A heating temperature sensor 46 that detects the temperature of the fluid inside the heating pathway 40, and a heating flow meter 48 that detects the mass flow or the volume flow of the fluid inside the heating pathway 40, are provided downstream from the heating valve 44 along the heating pathway 40.
Note that the path dimensions of the heating pathway 40 downstream from the heating unit 42 are preferably substantially uniform.
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 of the fluid, and not 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 the flow dimensions between the confluence unit 12 and the temperature adjustment unit 11 are, to the greatest degree possible, set such that the flow of the fluid that flows out from the cooling pathway 20, the bypass pathway 30, and the heating pathway 40 is not reduced, and such that an accumulation of fluid caused by that volume can be inhibited. This can be achieved by, for example, making the path dimensions of the confluence unit 12 and the path dimensions between the confluence unit 12 and the temperature adjustment unit 11 “1.5” times or less the path dimensions of each of the cooling pathway 20, the bypass pathway 30, and the heating pathway 40.
A pump 14 is provided between the confluence unit 12 and the temperature adjustment unit 11 as a flow means for causing fluid to flow in order to circulate the fluid. Here, the pump 14 is, for example, a diaphragm pump, a vortex pump, a cascade pump or the like. Furthermore, a damper 13 is connected to the pathway between the confluence unit 12 and the pump 14. The damper 13 comprises a container in which fluid is stored. Although fluid is stored in this container, 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 liquid occurs due to a change in temperature, this change will be absorbed due to the gas acting as a compressible fluid. In this way, hindrance to the flow of the liquid due to a change in the volume of the fluid will be avoided. In addition, the damper 13 comprises a breather valve 13a for allowing the gas to escape to the atmosphere when the pressure of the gas inside the container is higher than a predetermined pressure, and drawing in air when the pressure of the gas inside the container is less than a prescribed pressure that is lower than the predetermined pressure. In the figures, a construction in which the breather valve 13a comprises a pair of check valves is schematically illustrated, but a construction comprising a diaphragm valve or the like is in fact preferred. Preferably, the direction of travel of the pathway that connects the fluid pathway between the confluence unit 12 and temperature adjustment unit 11 with the damper 13 is substantially orthogonal to the direction in which the fluid flows from the confluence unit 12 to the temperature adjustment unit 11. In addition, it is preferred that the path dimensions of the aforementioned connecting pathway are approximately equal to or less than the path dimensions of the fluid pathway between the confluence unit 12 and the temperature adjustment unit 11.
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.
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 requested temperature value of the controlled object (requested 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 meter 28, the bypass flow meter 38, the heating flow meter 48, the supply temperature sensor 51 and others.
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 type of 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.
According to the temperature control device, the temperature inside the temperature adjustment unit 11 can be quickly changed in response to a change in requested 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 of the fluid from the cooling pathway 20, the bypass pathway 30, and the heating pathway 40, even when the requested temperature Tr is at any value within a range in which the temperature of the fluid inside the cooling pathway 20 is at or above the requested temperature Tr, and the temperature of the fluid inside the heating pathway 40 is at or below the requested temperature Tr.
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.
Assume that the fluid circulating in the temperature adjustment unit 11 is water, the temperature inside the cooling pathway 20 is “10° C.”, the temperature inside the heating pathway 40 is “70° C.”, and the flow 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° 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° 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.
Assuming that the flow 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.)×40(° C.)
=10(° C.)×Wa+43(° C.)×(20−Wa)
Because of this, Wa≈“1.8 L/min.”
Thus, the energy consumption Qa consumed in the cooling unit 22 is as follows.
Qa=(43−10)×1.8×60 (sec.)÷(860: conversion coefficient).
=4.1 kw
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)×10 (L/min.)×60 (sec.)÷860≈23 kW
Qc=(70−43)×10 (L/min.)×60 (sec.)÷860≈19 kW
Thus, the energy consumption Q is “42 kW”, and will be approximately “10” times that when the bypass pathway 30 is provided.
Next, the temperature control performed by the control device 50 according to the present embodiment will be described in detail.
In this series of steps, 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. Here, open loop control will be performed under the following conditions, and during this time feedback control will not be performed.
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 performing feedback control of the detected value Td to a target value Tt will be calculated. Here, the target value Tt is established based upon the requested temperature Tr, and is assumed to be the requested 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 Δ between the detected value Td and the target value Tt.
Next, in Step S16, the basic manipulating variable MB will be converted to each manipulating variable (opening ratio Va, Vb and Vc) of the cooling valve 24, the bypass valve 34, and the heating valve 44. Here, the relationship shown in
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 Δ between the detected value Td and the target value Tt.
When the process of Step S16 in
By employing feedback control as described above, the detected value Td can be placed at the target value Tt with a high degree of precision. 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 be created, 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.
As shown in
In this series of steps, it will first be determined in Step S20 whether or not a bias control flag is on, which is a flag for executing bias control that temporarily causes a large change in 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 ΔTr in the requested temperature Tr is equal to or greater than a threshold α. This process serves to determine whether or not a state exists in which the temperature of the controlled object cannot quickly achieve a requested change by means of the feedback control shown in
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 ΔTr 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 ΔTr 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 β. 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. Then, 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 β with respect to the temperature inside the heating pathway 40.
In contrast, in the event that it is determined in Step S26 that the amount of change ΔTr is equal to or greater than zero, then in Step S30, the target value Tt will be set to a value that is higher by a predetermined offset value γ than the temperature of the fluid inside the cooling pathway 20. Here, the setting of the offset value γ has the same meaning as the setting of the offset value β.
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 requested temperature Tr in Step S34. Furthermore, the bias control flag will be turned off and the measurement of 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 steps will be temporarily complete.
In this series of steps, 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 ΔTr in the target value Tt is equal to or greater than a threshold ε. In the event that it is determined that the absolute value of the amount of change ΔTr in the target value Tt is equal to or greater than the threshold ε, 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 of the open loop control time will begin.
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. This process will determine 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.
In the event that it is determined that the target value 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 value 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 Fc of the heating flow meter 48, and the temperature Tb of the bypass temperature sensor 36 and the flow Fb of the bypass flow 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. More particularly, the heating valve 44 and the bypass valve 34 will be manipulated so as to achieve the following formula.
Tt×(Fc+Fb)=Tc×Fc+Tb×Fb
In contrast, in the event that it is determined in Step S46 that the target value 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 value 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 Fa of the cooling flow meter 28, and the temperature Tb of the bypass temperature sensor 36 and the flow Fb of the bypass flow 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 operated so as to achieve the following formula.
Tt×(Fa+Fb)=Ta×Fa+Tb×Fb
When the process of Steps S48 and S50 is 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, so that feedback control does not begin within the bias continuation time period Tbi set by the process shown in
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 steps will be temporarily complete.
According to the present embodiment described in detail above, the following effects are obtained.
(1) The present embodiment comprises a 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 without passing 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 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.
(2) The pump 14 is provided downstream of the heating unit 42 that heats the fluid along the heating pathway 40. In this way, an increase in pressure in the heating pathway 40 inside the heating unit 42 due to the suction force produced by the pump 14 can be inhibited. Because of this, the withstand pressure required for the heating pathway 40 inside the heating unit 42 can be reduced.
(3) The heating valve 44 is provided upstream of the heating unit 42. Because of this, hindrance by the heating valve 44 on the effect of the pump 14 in reducing the pressure in the heating pathway 40 inside the heating unit 42 can be suitably avoided.
(4) The damper 13 is provided upstream of the pump 14 as a volume change absorption means that functions to absorb changes in the volume of fluid due to temperature. In this way, the circulation of the fluid can be suitably maintained when the volume of the fluid changes.
(5) The pump 14 is provided downstream of the confluence unit 12. In this way, a single pump 14 can suitably circulate fluid via the cooling pathway 20, the bypass pathway 30, and the heating pathway 40.
(6) The bypass pathway 30 employed when fluid is supplied from both the heating pathway 40 and the bypass pathway 30 to the temperature adjustment unit 11 is shared with the bypass pathway 30 employed when fluid is supplied from both the cooling pathway 20 and the bypass pathway 30 to the temperature adjustment unit 11. 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.
(7) 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.
(8) During feedback control, the basic manipulating variable MB that is based upon the degree of the deviation of the detected value Td from the target value Tt was converted to manipulating variable of the path dimension (opening ratio 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.
(9) Instead of performing feedback control over a predetermined time period after changing the target value Tt, 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.
(10) Open loop control is performed by adjusting 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 by adjusting 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.
(11) When a request 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 request. In this way, the temperature of the temperature adjustment unit 11 and the controlled object can be all the more quickly changed to the requested temperature.
A second embodiment will be described below with reference to the drawings that are focused on the points that differ from the first embodiment.
These discharge 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 the discharge pathways 60 and 62 to discharge a minute amount of fluid from the upstream side of the cooling pathway 20 and the heating pathway 40 to the downstream side when the cooling valve 24 and the heating valve 44 are closed.
In other words, when the discharge 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 in the area between the heating unit 42 or the cooling unit 22 and the confluence unit 12 along the heating pathway 40 and the cooling pathway 20. Thus, due to the effects of the temperature gradient on the temperature of the fluid to be discharged 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 inside the cooling unit 22 along the cooling pathway 20 and the temperature inside the heating unit 42 along the heating pathway 40. Because of this, the ability to control the open loop control when the target value Tt is changed may also decline.
In contrast to this, by providing the discharge pathways 60 and 62 in the present embodiment, temperature gradients downstream from the heating pathway 40 and the cooling pathway 20 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.
According to the present embodiment described above, the following effect will be obtained in addition to the effects (1) to (11) of the first embodiment.
(12) Discharge pathways 60 and 62 are provided that divert the fluid from the cooling valve 24 and the heating valve 44. In this way, temperature control when the target value Tt is changed can be more suitably performed.
A third embodiment will be described below with reference to the drawings that are focused on the points that differ from the first embodiment.
In this way, without providing the discharge pathways 60 and 62 shown in
According to the present embodiment described above, the following effect will be obtained in addition to the effects (1) to (11) of the first embodiment.
(13) The opening ratio Va of the cooling valve 24 and the opening ratio Vc of the heating valve 44 are set so as not to be 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.
A fourth embodiment will be described below with reference to the drawings that are focused on the points that differ from the first embodiment.
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 inside and/or 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 will continue 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.
In this series of steps, it will first be determined in Step S70 whether or not this 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 order the test mode. In the event that it is determined that the test mode is present, then in Step S72, a suggested bias continuation time period Tbi will be displayed to the user on a viewable display means. Here, the suggested bias continuation time period Tbi is preset in a range of suitable values for the controlled object presumed to be on the temperature control device.
Next, in Step S74, it will be determined whether or not the input of the bias continuation time period Tbi has occurred. This process will determine 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 process of Steps S72-S78 will be repeated.
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 steps will be temporarily complete.
According to the present embodiment described above, the following effect will be obtained in addition to the effects (1) to (11) of the first embodiment.
An open loop control adjustment support function is 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.
Note that each of the aforementioned embodiments can be modified as follows.
The changes from the first embodiment applied to the fourth embodiment may also be applied to the second and third embodiments.
In the fourth embodiment, the adjustment parameter used when performing adjustment support of open loop control was the bias continuation time period Tbi; however, 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
In the fourth embodiment, an adjustment was supported so as to allow a user to select a suitable adjustment parameter in accordance with the controlled object, however the present invention is not limited thereto. For example, a process may be performed such that when arbitrarily setting the initial value of each of the parameters, i.e., the bias continuation time period Tbi, the predetermined interval Top, and the offset values β, γ, 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.
In each of the aforementioned embodiments, the detected level Td of the fluid temperature downstream of the confluence unit 12 and upstream of the temperature adjustment unit 11 was feedback controlled to the target value Tt; however, the present invention is not limited thereto. For example, the detected value of the temperature of the fluid inside the temperature adjustment unit 11 may be feedback controlled to the target value Tt. In addition, the detected value of the temperature of the fluid supplied from the temperature adjustment unit 11 may, for example, be feedback controlled to the target value Tt.
In each of the aforementioned embodiments, the pump 14 and the damper 13 were provided downstream of the confluence unit 12; however, the present invention is not limited thereto. For example, the cooling pathway 20, the bypass pathway 30, and the heating pathway 40 may each be provided with a separate pump and damper. For example, with respect to the bypass pathway 30, a pump and damper may be provided on the upstream side of the bypass valve 34. In addition, with respect to the cooling pathway 20, a pump and damper may for example be provided between the cooling unit 22 and the cooling valve 24. Furthermore, with respect to the cooling pathway 20, a pump and damper may be provided on the upstream side of the cooling valve 24. Even in these situations, by providing a pump downstream of the heating unit 42 of the heating pathway 40, an increase in pressure in the heating pathway 40 can be inhibited, and the withstand pressure required for the heating pathway 40 can be reduced.
In each of the aforementioned embodiments, the cooling pathway 20, the bypass pathway 30, and the heating pathway 40 merge together in one location; however, the present invention is not limited thereto. For example, after the cooling pathway 20 and the bypass pathway 30 are merged together, the heating pathway 40 may be merged together with these downstream thereof. Even in these situations, it is preferable that the path dimensions of the confluence unit be made as small as possible, so that the velocity of the fluid flowing therein via the heating pathway 40, the cooling pathway 20, and the bypass pathway 30 is not reduced to the greatest extent possible. Here, the velocity of the fluid is the forward speed of the fluid in the direction of circulation.
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
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 requested temperature Tr, 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 only in this situation. 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.
In each of the aforementioned embodiments, the predetermined interval Top and the bias continuation time period Tbi in which open loop control will continue were set independently, however the present invention is not limited thereto, and they may be corresponding with each other.
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 precision 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.
Open loop control is not limited to that illustrated in the aforementioned embodiments. For example, open loop control may be performed while the flow may be acquired by employing the relationship between the basic manipulating variable and each manipulating variable (opening ratio Va, Vb and Vc) of the cooling valve 24, the bypass valve 34, and the heating valve 44 shown in
Note that when, for example, the temperature of the fluid inside the bypass pathway 30 is higher than the target value Tt, the opening ratio of the cooling valve 24 and the bypass valve 34 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 cooling pathway 20, without using the opening ratio shown in
Without limiting the use of feedback control, only the open loop control illustrated in Steps S48 and S50 of
The feedback control is not limited to being performed by converting the requested 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.
In each of the aforementioned embodiments, the bypass pathway 30 employed when fluid is supplied from both the heating pathway 40 and the bypass pathway 30 to the temperature adjustment unit 11 is shared with the bypass pathway 30 employed when fluid is supplied from both the cooling pathway 20 and the bypass pathway 30 to the temperature adjustment unit 11. However the present invention is not limited thereto. For example, the bypass pathway 30 employed when fluid is supplied from both the heating pathway 40 and the bypass pathway 30 to the temperature adjustment unit 11 may only partially share the bypass pathway 30 employed when fluid is supplied from both the cooling pathway 20 and the bypass pathway 30 to the temperature adjustment unit 11. Furthermore, each of these pathways may be separate. Even in this case, the effects of the aforementioned (1) to (5) and (7) to (11) of the first embodiment can be obtained.
The volume change absorption means that functions to absorb 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 container in which fluid is placed is not completely filled with fluid, and has a space filled with a gas. For example, a construction is possible in which the container is filled with fluid and has no gap, and the volume of the container is changed in response to a force applied by the fluid to the inner wall of the container. In addition, a part identical to the tank 100 shown in
In each of the aforementioned embodiments, the cooling valve 24, the bypass valve 34, and the heating valve 44 are employed as 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. However, the present invention is not limited thereto. For example, the adjustment means can adjust the path dimensions a step-wise manner. For example, it is possible to provide a plurality of each of these pathways, provide a valve on each of these pathways that fully opens and fully closes, 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 may be manipulated so that the downstream side of any of the cooling unit 22, the heating unit 42, and the return pathway 16 are connected to each of these pathways.
In addition, as shown in
Moreover, the shape of the temperature adjustment plate 10 is not limited to a rectangular shape, and may for example be a disk shape. Furthermore, the temperature adjustment unit 11 is not limited to being 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-289465 | Nov 2008 | JP | national |
