KR101752740B1

KR101752740B1 - Method for saving power in chiller apparatus for semiconductor fabricating process

Info

Publication number: KR101752740B1
Application number: KR1020150104304A
Authority: KR
Inventors: 박성일; 권진한; 송인환; 반윤식; 남정욱; 김학구
Original assignee: 유니셈(주)
Priority date: 2015-07-23
Filing date: 2015-07-23
Publication date: 2017-06-30
Also published as: KR20170011534A

Abstract

If the load is not applied to the process equipment, calculate the load applied to the process equipment connected to the chiller, judge whether the load is applied to the process equipment from the calculated load, operate the compressor at the minimum number of revolutions, And when the load is applied to the process equipment, the compressor is operated at a predetermined rotational speed according to the calculated load amount, and the hot gas valve is opened at the minimum opening ratio, the power consumption by the compressor is reduced and the hot The hot gas supplied from the gas valve is used as the heating source of the brine so that the power consumption by the brine heater is reduced.

Description

TECHNICAL FIELD [0001] The present invention relates to a power saving method for a chiller for a semiconductor process,

The present invention relates to a method of reducing power in a semiconductor process chiller.

Chiller is a temperature control device for stable process control in semiconductor device manufacturing process. Particularly, chiller is mainly used in etching and exposure process in various processes. It keeps the temperature of the electrode plate or chamber which generates excessive heat in the process constant, so that the wafer and glass are damaged due to high temperature, It prevents you.

Here, a brine is a solution or liquid having a low freezing point, usually an aqueous solution of CaCl ₂ and NaCl (cooling water) is used.

1 is a cooling system diagram of a conventional semiconductor process chiller.

The refrigerant is circulated through the compressor 100, the condenser 110, the electronic expansion valve 120, the evaporator 130, and the compressor 100, and the brine is circulated through the brine pump 210, the brine inlet 220, The brine pump 210 is circulated through the path of the brine tank 240 and the brine heater 242. The brine outlet 230 is connected to the evaporator 130 through the brine tank 240.

Accordingly, the refrigerant and the brine in the evaporator 130 overlap with each other to perform heat exchange. Two fluids, namely the refrigerant and the brine itself, are not mixed to effect heat exchange, but heat exchange takes place between them.

Heat exchange between the two fluids thus maintains a constant temperature at a specific location on the brine inlet 220 and outlets 230, e.g., A and B in FIG.

Most of the power consumption occurs in the driving unit. For example, most of the power consumption occurs in the constant-speed compressor 100 for compressing the refrigerant, the brine pump 240 for circulating the brain, and the brine heater 242 for heating the brine.

As described above, when the constant speed drive unit is selected and operated for each semiconductor process facility, the following problems occur.

However, the conventional chiller has a problem that the power consumption is constantly consumed due to the constant speed driving unit during the process of applying the thermal load to the semiconductor process equipment and the normal constant speed driving unit to which the load is not applied.

Also, there is a problem that the same amount of power is always consumed even when the load varies depending on the process method and the process facility.

Moreover, since the semiconductor process equipment must operate continuously for 365 days, the life of the compressor operating at the maximum capacity is shortened, which increases the maintenance cost and the management cost.

It is therefore an object of the present invention to provide a method for reducing the amount of power of a refrigerant chiller for semiconductor processing.

It is another object of the present invention to provide a method of controlling power consumption according to the load of a process facility.

Another object of the present invention is to provide a method capable of increasing the life of the compressor.

It is another object of the present invention to provide a method for reducing the maintenance cost and the management cost of the semiconductor process chiller.

The above object is achieved by a semiconductor process chiller comprising a variable speed compressor in a refrigerant line and an openable variable electronic hot gas valve provided in a branch path connecting a rear end of the compressor and a rear end of the expansion valve, Calculating a load applied to the process equipment; Determining whether a load is applied to the process facility from the calculated load amount; Operating the compressor at a minimum number of revolutions and opening the hot gas valve at a maximum opening rate when no load is applied to the process facility; And operating the compressor at a predetermined number of revolutions according to the calculated load when the load is applied to the process equipment, and opening the hot gas valve at a minimum opening ratio, wherein the load is not applied The power consumption by the compressor is reduced and the power consumption by the brine heater is reduced by using the hot gas supplied from the hot gas valve as a heating source of the brine. Power saving method.

Preferably, the load amount can be calculated from the following equation.
Load (kJ / sec) = Brine heat (kJ / sec ℃) * Temperature deviation (℃)
Here, the brine calorie (kJ / sec 占 폚) = the flow rate (m3 / s) 占 density (kg / m3)

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The temperature deviation is a difference between temperature values measured from a temperature sensor Sa installed at an inlet on a brine path and a temperature sensor Sb installed at an outlet, and the flow rate is a flow rate value measured from a flow meter installed in the inlet.

According to the above configuration, by applying the opening variable variable type electronic hot gas valve, the opening degree is minimized when the load is not applied to the process facility, so that the brine temperature can be lowered without operating the speed variable compressor at the maximum number of revolutions, Consumption can be greatly reduced.

Also, even if the load varies depending on the process method and the process facility, the number of revolutions of the compressor and the opening degree of the hot gas valve can be controlled to reduce power consumption by the compressor and power consumption by the brine heater.

In addition, since it is not necessary to maximize the number of revolutions of the compressor of the chiller in correspondence with the semiconductor process facility which is to be operated continuously for 365 days, the life of the compressor can be extended and the maintenance cost and the management cost can be reduced.

1 is a cooling system diagram of a conventional semiconductor process chiller.
2 is a cooling system diagram of a semiconductor process chiller applied to the present invention.
3 is a flowchart showing a power saving method of a semiconductor process chiller according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same configurations as those in the conventional art.

2 is a cooling system diagram of a semiconductor process chiller applied to the present invention.

The refrigerant is circulated to the compressor 102, the condenser 110, the electronic expansion valve 120, the evaporator 130, and the compressor 102, and the brine is circulated through the brine pump 210 to the brine (220) -> process equipment (300) -> brine outlet (230) -> evaporator (130) -> brine tank (240) -> brine heater (242) -> brine pump (210) do.

The refrigerant and the brine heat exchange each other in the evaporator 130 by mutually overlapping the refrigerant path and the brine path. In other words, the refrigerant and the brine themselves are not mixed, but heat exchange takes place between them.

In this embodiment, the compressor 102 is equipped with a variable speed compressor capable of inverter control, and an openable variable electronic hot gas valve 140 is connected to the branch path connecting the rear end of the compressor 102 and the rear end of the expansion valve 120 Respectively.

Therefore, the number of revolutions of the compressor 102 is efficiently controlled and the opening degree of the hot gas valve 140 is controlled to minimize the heating by the brine heater 242, thereby reducing the power consumption.

In other words, the speed variable compressor 102 can be driven and controlled by calculating the thermal load in place of the compressor (100 of FIG. 1) that performs the constant speed operation of the conventional semiconductor process chiller. The conventional hot gas valve supplies a fixed amount of hot compressed refrigerant to the evaporator 130 through the expansion valve 120 when the brine temperature is lowered. When the openable variable type electronic hot gas valve 140 is applied, when the load is not applied to the process facility, the opening degree of the compressor 102 is minimized so that the compressor 102 can be operated at the maximum rotation speed It is possible to lower the brine temperature without operating the compressor, and as a result, power consumption in the compressor 102 can be significantly reduced.

In addition, even when the load amount varies depending on the process method and the process facility, the number of revolutions of the variable-type compressor 102 and the opening degree of the hot gas valve 140 are controlled to reduce the power consumption by the compressor 102 and the power consumption by the brine heater 242 Power consumption can be reduced.

A temperature sensor Sa and a flow meter 222 are installed in the inlet 220 on the brine path and a temperature sensor Sb is installed on the outlet 230. The temperature value and the flow rate value measured therefrom are transmitted to the controller 10.

The opening degree, the speed and the amount of electric power are controlled by the control section 10 of the variable opening type hot gas valve 140, the variable speed compressor 102 and the brine heater 242.

3 is a flowchart showing a power saving method of a semiconductor process chiller according to the present invention.

First, a minimum value and a maximum value are set for the number of revolutions of the variable compressor 102, a plurality of values are set for the number of revolutions, and a plurality of opening rates are set for the hot gas valve 140 (step S31).

Next, the load applied to the process facility 300 is calculated (step S32).

The control unit 10 controls the flow rate of the flow rate measured by the temperature sensor Sa provided in the inlet 220 on the brine path and the temperature measured by the temperature sensor Sb provided on the outlet 230 and the flow rate measured from the flow meter 222 provided in the inlet 220 And the value is calculated using the following equation.

Flow rate (m3 / sec) = F

Temperature deviation (℃) = Sb - Sa

Heat (kJ / sec ℃) = mass * specific heat

(Where mass is the flow rate (m3 / sec) * density (kg / m3) and specific heat is kJ / kg DEG C)

Therefore, in consideration of the temperature deviation, the amount of heat required is the amount of heat (kJ / sec 占 폚) * temperature deviation (占 폚), and this required heat becomes the amount of heat of cooling.

The control unit 10 determines whether a load is applied to the process facility 300 from the calculated load amount (step S33).

The compressor 102 and the brine heater 242 are distinguished from each other by the operation in the case where the load is not applied from the calculated load (hereinafter referred to as no-load operation) and the operation in the case where the load is applied And controls the operation.

<No-load operation: S34>

The control unit 10 operates the variable compressor 102 at a minimum number of revolutions and opens the hot gas valve 140 at the maximum opening rate.

As a result, power consumption by the variable-capacity compressor 102 can be reduced to a minimum, and heating by the brine heater 242 can be performed by using hot gas supplied from the hot gas valve 140 as a heating source of the brine The power consumption by the brine heater 242 can be reduced.

The control unit 10 causes the variable compressor 102 to operate at a predetermined rotational speed in accordance with the calculated amount of cooling heat and opens the hot gas valve 140 at the minimum opening rate.

Therefore, the brine can be cooled by the refrigerant supplied from the expansion valve 120 while minimizing the influence of the hot gas from the hot gas valve 140. As a result, the conventional fixed type hot gas valve is applied, It is possible to prevent the cooling efficiency of the brine from being lowered by supplying the gas.

Meanwhile, the frequency variable brine pump 210 may be used in place of the constant speed brine pump 210 to reduce the power amount of the pump to the required flow rate.

Although the preferred embodiments of the present invention have been described above, various modifications and variations may be made by those skilled in the art. Therefore, the scope of the present invention should not be limited to the above-described embodiments but should be interpreted by the following claims.

10:
102: speed variable compressor
110: condenser
120: Expansion valve
140: Openable variable hot gas valve
130: Evaporator
210: Brine pump
220: Inlet
222: Flowmeter
230: Outlet
240: Brine tank
242: Brine heater

Claims

The present invention is applied to a semiconductor process chiller comprising a variable speed compressor in a refrigerant line and an openable variable electronic hot gas valve provided in a branch path connecting a rear end of the compressor and a rear end of the expansion valve,
Calculating a load applied to the process equipment connected to the chiller;
Determining whether a load is applied to the process facility from the calculated load amount;
Operating the compressor at a minimum number of revolutions and opening the hot gas valve at a maximum opening rate when no load is applied to the process facility; And
Operating the compressor at a predetermined number of revolutions in accordance with the calculated load amount and opening the hot gas valve at a minimum opening ratio when a load is applied to the process facility,
The power consumption by the compressor is reduced when the load is not applied and the power consumption by the brine heater is reduced by using the hot gas supplied from the hot gas valve as a heating source of the brine,
Wherein the load is calculated from the following equation.
Load (kJ / sec) = Brine heat (kJ / sec ℃) * Temperature deviation (℃)
(KJ / sec ° C) = flow rate (m 3 / sec) * density (kg / m 3)
The temperature deviation is a difference between the temperature value measured from the temperature sensor Sa installed at the inlet on the brine path and the temperature sensor Sb provided at the outlet, and the flow rate is the flow rate value measured from the flow meter installed in the inlet.

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