JP2000074585A - Temperature controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature controller for controlling the temperature of an object efficiently by circulating fluid regulated to a specified temperature using a small and inexpensive cooler while preventing the cooler from freezing. SOLUTION: Fluid returning from a load 11 is fed partially to a cooler 13 through a fixed branch valve 12 and distributed to the side of a super cooling tank, i.e., a tank C, and the side of a thermal tank, i.e., a tank A, through a variable branch valve 14 under control of a control section 18. Fluid on the side of tank A is heated by a heater 15 under control of a control section 18 before being fed to the tank A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for controlling the temperature of an object to be temperature-controlled by circulating and supplying a fluid adjusted to a predetermined temperature to an endothermic load. Also, the present invention relates to a temperature control device that performs efficient temperature control using a small and low-cost cooler.

[0002]

2. Description of the Related Art Conventionally, an object to be controlled, such as a semiconductor wafer, is mounted on a temperature control plate having a fluid passage, and a cold fluid adjusted to a predetermined temperature is circulated and supplied to the fluid passage. 2. Description of the Related Art A technique for controlling a temperature of an object to be controlled to a predetermined temperature is known.

More specifically, as shown in FIG. 5A, an endothermic load 4a such as a hot temperature control plate and a cooler 4b for cooling the return fluid from a fluid passage are connected by a pipe or the like and circulated. A path is formed, and the return fluid from the load 4a is cooled to a predetermined temperature T0 by the cooler 4b and supplied to the load 4a.

As described above, when the return fluid from the load 4a is cooled to a predetermined temperature Ta and supplied to the load 4a again, as shown in FIG. Is cooled by the amount of heat 4
The value of d is deprived, and the temperature-controlled object is temperature-controlled.

[0005]

However, FIG.
As shown in (a), when the fluid absorbs a large amount of heat from the load 4a in a very short time, the cooler 4b must have a cooling capacity to balance the instantaneous high load. Are becoming larger and more expensive,
Most of the time, the cooler will be overpowered and inefficient in terms of energy efficiency.

Further, as shown in FIG. 1B, the circulation path is branched into two paths R1 and R2, and the fluid flowing through the path R1 cooled using the cooler 5b and the fluid flowing through the bypass path R2 are separated. There is also known a technique in which the fluid temperature (T) is made constant by mixing in a mixer C and controlling the mixing ratio.
When the heat absorption amount of “a” is small, the flow rate of the fluid flowing through the path R1 becomes extremely small, and there is a problem that the cooler 5b freezes.

That is, unlike the heater which can freely perform on / off control or current control, the cooler 5b requires a certain amount of time to stabilize the cooling capacity, and always maintains a constant cooling state during operation. Therefore, when the amount of fluid flowing into the cooler 5b decreases, the temperature of the fluid becomes extremely low, so that the inside of the cooler freezes and the cooling function cannot be exhibited.

[0008] From these facts, it is extremely important to prevent freezing of the cooler when performing temperature control by circulating supply of fluid and to realize efficient temperature control by a small and low-cost cooler. It is an important issue.

Therefore, the present invention solves the above-mentioned problems, and
When controlling the temperature of an object to be temperature-controlled by circulating supply of fluid adjusted to a predetermined temperature, it is possible to prevent freezing of the cooler and perform efficient temperature control with a small and low-cost cooler. It is an object of the present invention to provide a temperature control device that can be used.

[0010]

In order to achieve the above object, according to a first aspect of the present invention, a fluid whose temperature has been adjusted to a predetermined temperature is circulated and supplied to an endothermic load to control the temperature of an object to be temperature controlled. In the temperature control device, a cooling unit that cools at least a part of the return fluid from the load, a supercooling tank that stores the fluid cooled by the cooling unit, a heating tank that stores the return fluid from the load, Mixing means for mixing the fluids in the cooling tank and the heating tank; first fluid dividing means for variably diverting the return fluid from the load and supplying one of the divided fluids to the cooling means in a predetermined amount or more; And control means for variably controlling the flow rate of the first fluid flow dividing means based on the target temperature of the fluid supplied to the load and the temperature of the fluid supplied to the load. Effective That.

(1) At least a fixed amount of fluid is constantly supplied to the cooling means, and the freezing of the cooling means can be prevented.

(2) Since the cooled fluid can be stored in the supercooling tank of the tank, even if the amount of heat absorbed by the heat-absorbing load in a short time is large, a small-sized and low-cost cooling means can be used. Can respond.

According to a second aspect of the present invention, there is provided a temperature control device for circulating and supplying a fluid adjusted to a predetermined temperature to an endothermic load to control the temperature of an object to be temperature controlled. A cooling unit that cools the unit, a supercooling tank that stores the fluid cooled by the cooling unit, a heating tank that stores the return fluid from the load, and a mixing unit that mixes the fluid in the supercooling tank and the heating tank. A first fluid splitting means for fixedly splitting the return fluid from the load, and supplying one of the split fluids to the cooling means in a predetermined amount or more;
A second fluid dividing unit that variably divides the fluid cooled by the cooling unit, supplies one of the divided fluids to the supercooling tank, and supplies the other fluid to the heating tank, and supplies the fluid to the load. And control means for variably controlling the flow rate of the second fluid flow dividing means based on the target temperature of the fluid to be supplied and the temperature of the fluid to be supplied to the load. (1) and (2) can be obtained.

In a third aspect of the present invention, the fluid cooled by the cooling means is diverted, one of the diverted fluids is supplied to the supercooling tank, and the other fluid is supplied to the heating tank.
And a control means for variably controlling a flow rate of the second fluid flow dividing means based on a target temperature of the fluid supplied to the load and a temperature of the fluid supplied to the load. With this configuration, it is possible to prevent the discharge temperature from decreasing.

Further, in the fourth invention, the apparatus further comprises a calorie supply means for supplying a predetermined amount of heat to the heat tank, so that even if the amount of heat absorbed from the load is small, the heat tank is useless. Appropriate temperature control can be performed while preventing a temperature drop.

According to a fifth aspect of the present invention, a fluid provided between the second fluid distribution means and the heating tank and having a predetermined amount of heat applied to the fluid supplied from the second fluid distribution means to the heating tank is provided. It is characterized by further comprising a calorie supply means for supplying heat.

According to a sixth aspect of the present invention, in the supercooling tank, the heating tank and the mixing means, fluids respectively overflowing from the supercooling tank and the heating tank are taken into the mixing tank, and the taken-in fluid is passed through the mixing tank. It is characterized in that an overflow tank for mixing is formed.

According to a seventh aspect of the present invention, the heat supply unit supplies a part or all of the heat taken from a part of the return fluid by the cooling unit to the fluid supplied to the heating tank. Therefore, temperature control with excellent energy efficiency can be performed.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration of the temperature control device used in the present embodiment will be described.

FIG. 1 is a diagram showing a configuration of a temperature control device used in the first embodiment.

The temperature control apparatus shown in FIG. 1 controls the variable control valve 14 and the heating element 15 by the control unit 18 to prevent freezing of the cooler 13 which is small and inexpensive, while maintaining the desired temperature in the overflow tank 16. The fluid adjusted to the above can be efficiently circulated and supplied to the load 11.

In particular, when the return fluid from the load 11 is branched by the fixed branch valve 12, a constant amount of the return fluid always passes through the cooler 13, so that the cooler 13 is prevented from freezing and is cooled. The fluid cooled by the vessel 13 is further branched by a variable branch valve 14 so that the flow rate of the fluid flowing into the supercooling tank C and the flow rate of the fluid flowing into the warming tank A can be adjusted. . When the fluid cooled by the cooler 13 flows into the A tank as it is,
Since the temperature of the fluid in the tank A decreases, the heat is used to replenish the heat of the fluid cooled by the cooler 13 using the heating element 15.

As described above, in this temperature control device, a constant amount of fluid is always passed through the cooler 13 to prevent the cooler 13 from freezing, and a small cooler is used in the supercooling tank. A certain C tank can hold the cooled fluid.

For this reason, even when the load 11 performs high heat absorption in a short time, the high-temperature fluid overflowing from the load 11 to the mixing tank B through the tank A and the high-temperature fluid flowing from the tank C to the tank B By mixing and canceling the overflowing supercooled fluid, the discharge temperature T can be adjusted to be constant.

As shown in FIG. 1, this temperature control device
A fixed branch valve 12, a cooler 13, a variable branch valve 14,
Heating element 15, overflow tank 16, pump 1
7 and a control unit 18.

The fixed branch valve 12 is a fixed valve that distributes the return fluid from the load 11 at a fixed ratio to a path for the cooler 13 and a path for the tank A of the overflow tank.

The cooler 13 is a cooler such as a chiller for cooling the fluid distributed by the fixed branch valve 12. The cooler 13 is not required to have a cooling performance for instantaneously canceling the amount of heat absorbed by the load 11 in a short time, so that a small and inexpensive cooler can be used. The reason is,
Since the supercooled fluid is stored in the tank C (supercooling tank) of the overflow tank 16, even if the high-temperature fluid flows into the tank C for temporarily canceling the heat absorption, the tank B is also transferred to the tank B. This is because the temperature of the overflowing fluid can be kept low.

The variable branch valve 14 is a variable valve that distributes the fluid flowing out of the cooler 13 to a path for the C tank of the overflow tank 16 and a path for the heating element 15, and is controlled by a control unit 18 described later. You.

The heating element 15 is a heating means such as a heater that heats the fluid cooled by the cooler 13 and distributed by the variable branch valve 14 under the control of the control unit 18. In the present embodiment, if the fluid that has flowed into the cooler 13 flows into the A tank of the overflow tank 16 as it is, the fluid temperature of the fluid stored in the A tank decreases, and as a result, the fluid at a predetermined temperature is removed. The heating element 15 is provided because it cannot be supplied to the load 11. In addition, this heating element 15 can also be arrange | positioned in A tank which is a thermal tank.

The overflow tank 16 has a tank A for storing a return fluid having a high temperature from the load 11, a tank C for storing a part of the return fluid cooled by the cooler 13,
A tank and a tank B for receiving and mixing the fluid overflowing from the tank C. It should be noted that other tanks can be used in place of the overflow tank 16, but at least a function of temporarily storing the supercooled fluid, mixing the cooling fluid with the warm fluid, and outputting at a constant temperature is required. is there.

The pump 17 includes an overflow tank 16
Is a pump for circulating and supplying the fluid at a constant temperature in the tank B to the load 11.

The controller 18 controls the overflow tank 16
The control unit controls the variable branch valve 14 based on the temperature of each tank in the inside and the target discharge temperature, and controls the heating element 15 so as not to cool the tank A too much.

The configuration of the temperature control device according to the present embodiment has been described above.

Next, the processing contents of each part of the temperature control device shown in FIG. 1 will be specifically described according to the order of circulation of the fluid.

First, the fluid in the tank B of the overflow tank 16 is supplied to the heat absorbing load 11 by the pump 17. The fluid whose temperature has risen due to the amount of heat received from the load 11 is divided by the fixed branch valve 12, and one of the fluids is stored in the A tank and the other fluid is the cooler 1
Cooled in 3.

As described above, in this temperature control device, a constant amount of fluid is always supplied to the cooler 13.
As shown in (b), the amount of fluid passing through the cooler 13 does not significantly decrease, and the cooler 13 does not freeze.

However, if it is assumed that all the fluid cooled by the cooler 13 is always stored in the C tank, the flow rate flowing into the A tank and the C tank is a constant value determined by the fixed branch valve 12, so that the suction from the load 11 is performed. Fluctuations in the amount of heat are transmitted to the temperature of the B tank. Therefore, it is necessary to release a part of the fluid cooled by the cooler 13 to a portion other than the C tank and adjust the flow rate flowing into the A tank and the C tank, but if the fluid to be released is simply sent to the A tank or the B tank. When the temperature of the return fluid flowing out of the load 11 is so low that the temperature of the mixing tank cannot be kept constant when the tank A is not warm, the temperature of the fluid circulating to the load 11 decreases, which causes a problem. .

For this reason, the fluid cooled by the cooler 13 is:
Under the control of the controller 18, the fluid is diverted to the A tank side and the C tank side of the overflow tank 16, and the fluid diverted to the A tank side is heated by the heating element 15 and then supplied to the A tank.

Then, the overflow tank 16
Since the fluids in the tanks A and C overflow and flow into the tank B due to the supply of the fluid therein, the high-temperature fluid from the tank A and the low-temperature fluid from the tank C are mixed in the tank B.

Since a part of the fluid cooled by the cooler 13 is always stored in a fixed amount of the C tank, even if the load 11 absorbs a large amount of heat in a short period of time, the size of the fluid can be reduced. -It can respond by the low-cost cooler 13.

Next, a control procedure of the variable branch valve 14 and the heating element 15 by the control unit 18 shown in FIG. 1 will be described.

FIG. 2 is a flowchart showing a control procedure of the variable branch valve 14 and the heating element 15 by the control unit 18 shown in FIG.

As shown in the figure, a target temperature TO of the fluid in the B tank of the overflow tank 16 is set (step 201), and the respective temperatures TA, TB of the A tank, the B tank and the C tank of the overflow tank 16 are set. And TC are measured (step 202), a branch rate γ of the variable branch valve 14 is calculated based on these temperatures (step 203).
The variable branch valve 14 is driven according to the calculated branch ratio γ (step 204).

Specifically, assuming that the branching rate of the fixed branch valve 12 is k and the proportional gain is β, TA × {k + (1-k) γ} + TC × (1-k) (1-γ) -TB × 1 =
Since the relational expression β (TO−TB) holds, the branch rate γ of the variable branch valve 14
Is γ = {β (TO−TB) + TB−kTA− (1-k) TC} / ｛(1-
k) It can be calculated from the formula of (TA-TC)｝. It should be noted that instead of the temperature B of the tank B, the overflow tank 16 and the load 11
And the temperature T on the fluid supply path between the two. When T is used instead of TB, a time delay is added and control becomes difficult, but this is more natural from the viewpoint of keeping the supply temperature to the load 11 constant.

In parallel with the control of the variable branch valve 14, the calorific value Q of the heating element 15 is calculated (step 20).
5) The heating element 15 is driven according to the calculated heating value Q (step 206).

Specifically, the maximum heating value of the heating element 15 is Q
Assuming that max, the lower limit of tank A is TA, min (> TO), and the proportional gain is δ, the heat generation amount Q of the heating element 15 is Q = max {Qmax−δ (TA−TA, min), 0}. It is obtained from the calculation formula. Note that max (i, j) is i
And j, whichever is greater.

Next, an example of a simulation result of the temperature controller according to the present invention shown in FIG. 1 will be described in comparison with a simulation result of the conventional temperature controller. In addition,
Here, the discharge flow rate from the tank is 140 l / min,
The case where the overflow tank capacity is 200 l and a chiller having a cooling capacity of 34 kW is used is shown.

FIG. 3A is a diagram showing a simulation result when a conventional temperature control device is used. The conventional temperature control device supplies fluid in a tank to a load, 8 is assumed to be cooled by a chiller and returned to the tank.

As shown in FIG. 5A, the temperature of the fluid returned from the load peaks at about 50 ° C. in about 30 seconds, and then rapidly returns to the original 10 ° C.

On the other hand, the temperature of the fluid supplied to the load is 30 seconds at which the temperature of the fluid returned from the load reaches a peak.
It rises after the passage. Therefore, the temperature drop of the return fluid is weakened by the increase of the supply temperature, and becomes stable at about 10 ° C. after about 100 seconds.

As described above, when the conventional temperature control device is used, if the temperature of the return fluid from the load is high, the temperature of the fluid supplied to the load is ± 1.67 ° C. due to the influence of the return fluid. It fluctuates to the extent.

On the other hand, FIG. 6B shows a simulation result when the temperature control device according to the present invention is used.

As shown in FIG. 5B, the temperature of the fluid returned from the load peaks at about 50 ° C. in about 30 seconds, and thereafter, peaks at about 10 ° C., as in the case of the prior art shown in FIG. It will be around ℃.

However, the temperature of the fluid supplied to the load is always stable at 10 ° C., and is not affected by the temperature of the fluid returned from the load.

The reason is that the temperatures of the tank A, which is a heating tank, and the tank C, which is a supercooling layer, fluctuate under the influence of the temperature of the fluid returned from the load. This is because the variable branch valve 14 is controlled so that the temperature of the tank B can be kept constant.

As described above, it can be understood that the use of the temperature control device according to the present invention not only prevents the cooling of the cooler but also allows the fluid constantly adjusted to a constant temperature to be stably supplied to the load.

As described above, in this embodiment,
A part of the return fluid from the load 11 is caused to flow to the cooler 13 by the fixed branch valve 12, and the fluid flowing out of the cooler 13 is controlled by the variable branch valve 14 controlled by the control unit 18 to the C tank side as the supercooling tank and Since the fluid is distributed to the tank A, which is a heating tank, and the fluid in the tank A is heated by the heating element 15 controlled by the control unit 18 and then flows out to the tank A, the following effects are obtained. .

1) It is possible to always pass a certain amount of fluid through the cooler 13 to prevent the cooler 13 from freezing.

2) By storing the fluid cooled by the cooler 13 in the C tank, which is a supercooling tank, a small and inexpensive cooler can be used even when the load 11 absorbs a large amount of heat in a short time. 13 can be handled.

In the above description, the amount of heat radiated by the fluid in the cooler 13 is supplemented by the amount of heat supplied by the heating element 15, but instead of the amount of heat supplied by the heating element 15, the cooler 13 The amount of heat obtained from the fluid during cooling can also be used.

For example, as shown in FIG. 4, a chiller 31 is used as a cooler for cooling the return fluid, and the chiller 31 takes away from the return fluid instead of the heating element 15 of the temperature control device shown in FIG. A heat exchanger 32 to which heat is supplied can be used. In this case, the control unit 34 controls the variable branch valve 14 and the three-way valve 33.

The chiller 31 is configured to circulate the refrigerant between the evaporator and the condenser through a chiller unit (not shown). In this evaporator, the fluid flowing from the fixed branch valve 12 to the variable branch valve 14 and the refrigerant , The fluid is cooled, and the refrigerant is cooled by exchanging heat between the refrigerant and the cooling water in the condenser.

As described above, instead of providing the heating element 15 completely separately from the cooler 13 as in the temperature control device shown in FIG. 1, the amount of heat taken from the fluid by the chiller 31 as the cooler is stored in the overflow tank 16. By returning to the cooling fluid flowing into the tank A again, there is no need to externally apply the energy of the heating element 15, and temperature control with excellent energy efficiency can be performed.

The auxiliary cooling units f1 and f2 are cooling units for auxiliary cooling the return fluid from the load 11 and the fluid flowing into the A tank. These are provided for the purpose of weakening the heat load applied to the tank by canceling a part of the amount of heat absorbed by the load 11 in a short time, and are not necessarily essential to the present invention.

In the present embodiment, the auxiliary cooling unit f1
And f2 are both used, but the present invention is not limited to this, and one or both of them can be deleted.

In the present embodiment, the fixed branch valve 12
Although the return fluid is divided into the cooler 13 and the A tank by using the above, the present invention is not limited to this, and it is also possible to use a variable branch valve. However, when a variable branch valve is used, the supply of fluid to the cooler 13 must not be significantly reduced, and at least a constant amount of fluid must be supplied at all times. When a variable branch valve is used instead of the fixed branch valve 12, the variable branch valve 1
4 is not required. This is shown in FIG.

The difference from the apparatus shown in FIG. 1 is that the branch valve 71 is variable and that the fluid in the A and C tanks is mixed using a three-way valve instead of an overflow tank as the mixing means 73. is there. In the variable branch valve 71, the branch rate is controlled based on the target temperature of the fluid supplied to the load 11 and the temperature of the fluid supplied to the load. The temperature of the fluid supplied to the load may be 1) fluid temperature between the pump and the load 2) fluid temperature between the B tank and the pump 3) fluid temperature in the B tank. In the case of 1), the accuracy is the highest because there is no influence of heat generated by the pump 17.

Further, in this embodiment, the variable branch valve 1
Although the case where one of the divided fluids is supplied to the tank A in 4 is shown, the present invention is not limited to this, and it is also possible to supply the fluid to the tank B.

FIG. 7B uses an overflow tank for the fluid from the supercooling tank C to the heating tank A as the mixing means. The variable branch valve 12 can be varied by heating the tank (A tank), supercooling layer (C tank),
The temperature of the fluid supplied from 1 to the heating tank (A tank) is measured by a sensor indicated by a black circle in the figure, and control is performed based on these temperatures.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a temperature control device used in the present embodiment.

FIG. 2 is a flowchart showing a processing procedure of a control unit shown in FIG. 1;

FIG. 3 is a diagram showing an example of a simulation result by the temperature control device shown in FIG. 1;

FIG. 4 is a diagram showing another configuration of the temperature control device used in the present embodiment.

FIG. 5 is a diagram showing a configuration and the like of a conventional temperature control device.

FIG. 6 is a diagram for explaining a problem of a conventional temperature control device.

FIG. 7 is a diagram showing a configuration when a variable branch valve is used instead of the fixed branch valve shown in FIG. 1;

FIG. 8 is a diagram showing a configuration of a conventional temperature control device which is a premise of the simulation shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Load 12 ... Fixed branch valve 13 ... Cooler 14 ... Variable branch valve 15 ... Heating element 16 ... Overflow tank A tank ... Heating tank B tank ... Mixing tank C tank ... Supercooling tank 17 ... Pump 18 ... Control part 31 ... Chiller 32 heat exchanger 33 three-way valve 34 control unit 71 variable branch valve 72 control unit 73 mixing means

Claims (7)

[Claims] 1. A temperature control device for circulating and supplying a fluid adjusted to a predetermined temperature to an endothermic load to control the temperature of an object to be temperature-controlled, wherein cooling means for cooling at least a part of a return fluid from the load. (13), a supercooling tank for storing a fluid cooled by the cooling means, a heating tank for storing a return fluid from the load, and a mixing means (73) for mixing the fluid in the supercooling tank and the heating tank. A first fluid branching means (71) for variably diverting the return fluid from the load and supplying one of the diverted fluids to the cooling means in a predetermined amount or more; a target temperature of the fluid supplied to the load; A temperature control device comprising: a control unit (72) that variably controls a flow dividing ratio of the first fluid flow dividing unit based on a temperature of a fluid supplied to a load. 2. A temperature control device for circulating and supplying a fluid adjusted to a predetermined temperature to an endothermic load to control the temperature of an object to be temperature controlled, wherein a cooling means for cooling at least a part of a return fluid from the load. (13), a supercooling tank for storing the fluid cooled by the cooling means, a heating tank for storing the return fluid from the load, a mixing means for mixing the fluid in the supercooling tank and the heating tank, and the load From the fixed fluid, and supplies one of the divided fluids to the cooling means in a predetermined amount or more.
A fluid dividing means (12) for variably dividing the fluid cooled by the cooling means, supplying one of the divided fluids to the supercooling tank, and supplying the other fluid to the heating tank. A fluid dividing means (14); and a control means (18) for variably controlling a dividing rate of the second fluid dividing means based on a target temperature of the fluid supplied to the load and a temperature of the fluid supplied to the load. A temperature control device, comprising: 3. A second fluid dividing means (14) for dividing the fluid cooled by the cooling means, supplying one of the divided fluids to the supercooling tank, and supplying the other fluid to the heating tank. And a control means (18) for variably controlling a flow rate of the second fluid flow dividing means based on a target temperature of the fluid supplied to the load and a temperature of the fluid supplied to the load. The temperature control device according to claim 1, wherein: 4. The temperature control device according to claim 1, further comprising a calorie supply means (15) for supplying a predetermined calorie to said thermal bath. 5. A calorie supply means provided between the second fluid diverting means and the heating tank, for supplying a predetermined amount of heat to the fluid supplied from the second fluid diverting means to the heating tank. 3. The system according to claim 2, further comprising (15).
Or the temperature control device according to 3. 6. The supercooling tank, the heating tank and the mixing means form an overflow tank which takes in the fluid overflowing from the supercooling tank and the heating tank into the mixing tank and mixes the taken-in fluid in the mixing tank. The temperature control device according to claim 1, wherein the temperature control is performed. 7. The heat supply device according to claim 4, wherein the heat supply unit supplies a part or all of the heat removed from a part of the return fluid by the cooling unit to the fluid supplied to the heating tank. Or the temperature controller according to 5.