JP2000249056A - Method and device for controlling operation of cryopump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cryopump operation control method capable of saving energy through reduction of a consumption of refrigerant gas and reducing an operation cost. SOLUTION: In a method for controlling operation of a cryopump 10, a first heater and a first temperature sensor are arranged at a first stage cooling part, a second heater and a second temperature sensor are mounted on a second stage cooling part, the temperatures of the first and second stage cooling parts are measured by respective temperature sensors, and on the basis of a difference between a measurement temperature and a set temperature set according to the kind of feed gas supplied to the cryopump 10, the respective heaters are operated by a cryopump controller 32 and a control box 31 to control the temperature of the respective cooling parts. Since the cooling parts are not cooled more than necessary, the consumption of refrigerant gas is reduced, energy is saved, and an operation cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cryopump operation control method and operation control device.

[0002]

2. Description of the Related Art Conventionally, a cryopump using a cryogenic refrigerator such as a GM cycle refrigerator or a Stirling cycle refrigerator has been known. As such a cryopump, one described in JP-A-1-305173 is known.

In this conventional cryopump, in order to prevent overhang, a temperature sensor and a heating device are provided in a first stage cooling unit controlled at 50 to 160K, and the temperature of the first stage cooling unit is controlled. Had control. The second-stage cooling unit cooled to an extremely low temperature is not provided with a temperature sensor, and only a heating device for heating the second-stage cooling unit to shorten the regeneration time when the cryopump is regenerated. Was provided.

[0004]

In such a conventional cryopump, the heating device of the second-stage cooling section was not operated during the operation, and was operated without load. For this reason, the cooling unit in the second stage is set at a temperature lower than the required temperature (for example,
(0K or less), but the temperature was not specifically controlled.

For this reason, depending on the state of the cryopump, such as immediately after maintenance or after a certain period of use, the cooling unit in the second stage may be 10 to 2 times.
It was about 0K.

However, the present applicant has found a problem that even if the temperature of the cooling section in the second stage varies only in the range of about 10 to 20 K, a large difference occurs in the consumption of the refrigerant gas used.

An object of the present invention is to provide an operation control method and an operation control device for a cryopump, which can reduce the consumption of refrigerant gas, save energy, and reduce the operation cost.

Further, in recent years, there have been cases where a plurality of cryopumps are incorporated in a plant apparatus or the like. At this time, one compressor for supplying a refrigerant gas such as helium to a plurality of cryopumps is usually provided for one cryopump.
By increasing the capacity of the compressor and connecting one compressor to a plurality of, for example, two or three cryopumps, a system that saves space and reduces costs has been developed.

[0009] However, when a plurality of cryopumps are connected to such a single compressor, performance problems may occur depending on the state of each cryopump. That is, a refrigerator (eg, a GM cycle refrigerator) used for a cryopump generally requires a helium gas, which is a working gas, as the temperature of a low-temperature cooling unit (a second-stage cooling unit) decreases. The flow rate increases. For example, the helium gas flow rate in a cryopump having a diameter of 200 mm is 730 NL / min when the temperature of the first stage cooling unit is 50K and the temperature of the second stage cooling unit is 9K.
When the temperature of the first-stage cooling unit was 65K and the temperature of the second-stage cooling unit was 15K, it was 480 NL / min.

Therefore, four cryopumps are 65K /
When operating at 15K (second stage cooling unit temperature / first stage cooling unit temperature), the total flow rate is 1920 NL / min, and when operating at 50K / 9K, the total flow rate is 2920 NL / min. Become.

The refrigerating performance of the refrigerator is proportional to the pressure difference between the supply pressure (high pressure) and the return pressure (low pressure) of the working gas. If the pressure difference is small, sufficient refrigerating performance cannot be obtained. FIG.
According to the flow characteristics of the compressor shown in FIG.
When the pressure is 0 NL / min, the low pressure is 0.81 MPa, and when the flow rate is 2920 NL / min, the pressure is 1.25 MPa.
a. Therefore, when the pressure on the high pressure side is 2.1 MPa, the differential pressure is 1.29 M at a flow rate of 1920 NL / min.
Pa, which is a value that can operate four cryopumps with sufficient refrigeration performance. On the other hand, the differential pressure at a flow rate of 2920 NL / min is as small as 0.85 MPa, and sufficient refrigeration performance cannot be exhibited.

When the differential pressure is small, the refrigerating performance decreases, the temperature of each cooling section increases, the flow rate of the working gas decreases, and the differential pressure increases. As a result, the temperature becomes stable at an appropriate temperature.
Even if the temperature was reduced to about 9K because the temperature of the cooling section was not controlled, there was no problem in system operation.

However, there have been problems in the following cases. In other words, when the heat load from the apparatus differs depending on each cryopump, the cooling unit of the second stage is 9K.
When the refrigeration performance is reduced due to an increase in the working gas flow rate, the capacity of the cryopump having a larger heat load is insufficient, and the cryopump cannot be used.

Also, three cryopumps are operating and one
Even when the table is cooled down from room temperature, there is a problem that the cooling down time is prolonged due to a decrease in refrigeration performance. For example, three cryopumps are 65K
/ 15K and 50K / 9K, the total flow rate is 1440 NL / min, 2190 NL / m, respectively.
When operating at a low temperature of 50K / 9K calculated from the differential pressure, the cool-down time is increased by about 25% as compared with the case of 65K / 15K, and actually a larger difference is generated. There was a problem.

A second object of the present invention is to provide a cryopump operation control method and operation control device capable of suppressing a decrease in the cooling performance of each cryopump when a plurality of cryopumps are connected to one compressor. Is to provide.

[0016]

SUMMARY OF THE INVENTION The present invention is directed to a first and second cryopanel surfaces and a first and second cryopanel surface for cooling the first and second cryopanel surfaces. A cryopump operation control method including a cooling unit, wherein a first heating device and a first temperature sensor are provided in the first stage cooling unit, and a second heating unit and a second temperature unit are provided in the second stage cooling unit. A heating device and a second temperature sensor are provided, and the temperatures of the first and second stage cooling units are measured by the respective temperature sensors, and the temperature is determined according to the measured temperature and the type of supply gas supplied to the cryopump. And controlling the temperature of each cooling unit by operating each of the heating devices based on a difference from a set temperature set by the control unit.

According to such an operation control method, the temperature of each cooling section of the first and second stages is measured and the temperature of each cooling section is controlled to a predetermined temperature. The above cooling can be prevented, the consumption of refrigerant gas (working gas) can be reduced, and energy can be saved.
Operating costs can also be reduced.

According to a second aspect of the present invention, there are provided first and second cryopanel surfaces, and first and second cryopanel surfaces for cooling the first and second cryopanel surfaces.
A cryopump operation control method comprising: a plurality of stages of cryopumps, wherein a plurality of the cryopumps are provided, and the first and second stages of the plurality of cryopumps have first and second stages. A second heating device and first and second temperature sensors are provided, respectively, and a refrigerant gas is supplied from one gas supply device to the plurality of cryopumps, and the first stage of each of the cryopumps is provided. And the temperature of the second stage cooling unit is measured by the temperature sensor, and based on a difference between the measured temperature and a set temperature set according to the type of supply gas supplied to the cryopump, each of the heating devices is measured. To control the temperature of each cooling unit.

According to such an operation control method, since the temperatures of the respective cooling portions of the respective cryopumps are individually controlled, it is possible to prevent the temperature of the cooling portions from being lowered more than necessary, and to control the refrigerant gas (actuation). Gas) can be reduced, energy can be saved, and operating costs can be reduced.
Further, since the flow rate of the refrigerant gas can be suppressed, 1
Even when a plurality of cryopumps are connected to one gas supply device (compressor), sufficient cooling performance can be obtained with each cryopump.

For this reason, even when the heat loads of the respective cryopumps are different, the temperature of the cooling portion of the cryopump having a small heat load does not decrease unilaterally, and thus the cryopumps exhibit sufficient cooling performance. can do. In addition, even when a cryopump is being cooled down, the temperature of the other cryopumps during operation is not excessively reduced, so that a decrease in refrigeration performance can be suppressed and a cooldown time can be reduced. .

When a plurality of cryopumps are connected to one compressor, the temperature of the first stage cooling section of each of the cryopumps is controlled to the same temperature, and the temperature of the first cryopump of each of the cryopumps is controlled. It is preferable to control the temperature of the two-stage cooling unit to the same temperature. In this way, there is no difference in gas consumption between the cryopumps, so that control can be performed easily.

The temperature of the second stage cooling section is 14
It is preferable to operate while maintaining at ~ 18K. More preferably, the temperature of the second stage cooling section is 15-16K.
When the temperature of the second-stage cooling unit is reduced to 13 K or less, the consumption of the refrigerant gas increases, and the operating cost increases. On the other hand,
If the temperature of the second-stage cooling section is as high as 19 K or more, the required refrigeration performance cannot be obtained. On the other hand, if the temperature is maintained at 14 to 18K, necessary refrigeration performance can be obtained while suppressing gas consumption, and cost performance can be improved.

The present invention also provides a first and second cryopanel surface, and a first and second cooling unit for cooling the first and second cryopanel surfaces. An operation control device for a cryopump provided with the first stage and the second stage cooling units, respectively.
And a second heating device, first and second temperature sensors provided in the first and second stage cooling units, respectively, and a temperature of the first and second stage cooling units to the temperature. The temperature of each cooling unit is controlled by operating each of the heating devices based on a difference between a measured temperature measured by a sensor and a set temperature set according to a type of supply gas supplied to the cryopump. And a control unit.

According to the present invention, the temperature of each cooling unit in the first and second stages is measured by the temperature sensor to control the heating device, thereby controlling the temperature of each cooling unit to a predetermined temperature. it can. For this reason, each cooling unit can be prevented from being cooled more than necessary, the consumption of the refrigerant gas (working gas) can be reduced, energy can be saved, and the operating cost can be reduced.

Further, the present invention provides a first-stage and a second-stage cryopanel surface, and a first-stage and a second-stage cooling unit for cooling the first-stage and the second-stage cryopanel surface. An operation control device for a cryopump, wherein a plurality of the cryopumps are provided, and one gas supply device for supplying a refrigerant gas to the plurality of cryopumps is provided, and First and second heating devices provided in the first-stage and second-stage cooling units, respectively, first and second temperature sensors provided in the first-stage and second-stage cooling units, A control unit that controls the temperature of the first-stage cooling unit of each of the cryopumps and controls the temperature of the second-stage cooling unit of each of the cryopumps.

According to such an operation control device, since the temperature of each cooling section of each cryopump is individually controlled, it is possible to prevent the temperature of the cooling section from lowering unnecessarily, and to control the refrigerant gas (actuation). Gas) can be reduced, energy can be saved, and operating costs can be reduced.
Further, since the flow rate of the refrigerant gas can be suppressed, 1
Even if a plurality of cryopumps are connected to one compressor, sufficient cooling performance can be obtained with each cryopump.

For this reason, even when the heat loads of the cryopumps are different, the temperature of the cooling section of the cryopumps having a small heat load does not decrease unilaterally, so that the cryopumps can sufficiently exhibit the cooling performance. can do. In addition, even when a cryopump is being cooled down, the temperature of the other cryopumps during operation is not excessively reduced, so that a decrease in refrigeration performance can be suppressed and a cooldown time can be reduced. .

[0028]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an operation control device 30 of a cryopump 10 according to the present embodiment. The operation control device 30 includes the cryopump 10
And controls the operation of the compressor 20.
In the present embodiment, six cryopumps 10 and two compressors (gas supply devices) 20 are provided, and three cryopumps 10 are connected to one compressor 20.

The operation control unit 30 includes a total of six control boxes 31 provided for the respective cryopumps 10 as a control unit, and one cryopump controller 32 connected to these control boxes 31. It is comprised including.

The cryopump 10 has a refrigeration unit 51 composed of a GM (Gifford-McMahon) cycle refrigerator as shown in FIGS. Further, pipes 21 and 22 for supplying helium gas, which is a working gas (refrigerant gas), from the compressor 20 to each of the refrigeration units 51 and returning the gas to the compressor 20 are provided.

As shown in FIG. 2, the cryopump 10 has a pipe 1 for supplying and exhausting a purge gas.
1 and 12 are connected, and a pipe 1 for roughing exhaust is provided.
3 are connected. Each of these pipes 11 to 13 is provided to be branched from each cryopump 10,
Valves 14 to 16 for opening and closing the flow path are provided in each branch pipe portion.
Are provided corresponding to the respective cryopumps 10.

More specifically, the pipings 11 and 12 are provided with solenoid valves 14 and 15 controlled by a control box 31, and the piping 13 is supplied by a solenoid valve 17 controlled by the control box 31. A pneumatic valve 16 is provided which is actuated by a driving compressed gas. Also,
The pipe 13 is provided with first and second pressure gauges 18 and 19 with a pneumatic valve 16 interposed therebetween. Signals from the pressure gauges 18 and 19 are transmitted to a cryopump controller 32 via a control box 31. I have.

Each compressor 20 is also connected to the cryopump controller 3 via a control box 31.
2 is controlled.

As shown in FIGS. 3 and 4, a refrigeration unit 51 provided in each cryopump 10 is provided with a first-stage cooling section (first heat station) 52 and an upper portion of the first-stage cooling section 52. And a second-stage cooling unit (second heat station) 53 whose temperature is lower than that of the first-stage cooling unit 52.

At the outer periphery of the upper end of the first-stage cooling section 52, a bottomed cylindrical radiation shield 60 which is a heat radiation shielding member surface-treated with nickel plating is attached, and an opening above the radiation shield 60 is provided. A baffle 61 cooled to about 70 to 100 K is attached to the section, and the second-stage cooling section 53 is surrounded by the radiation shield 60.

On the other hand, the second stage cooling section 53
A cold panel 62 cooled to about K is attached, and a granular charcoal 63 for absorbing and exhausting a gas that is not sufficiently condensed at about 10 to 20 K is attached to the cold panel 62. The entire components such as the cooling units (heat stations) 52 and 53 and the radiation shield 60 are housed in a vacuum chamber 64 made of stainless steel.

First stage cooling unit 52 and second stage cooling unit 53
As shown in FIG. 4, first and second temperature sensors 35 and 36, and heaters 37 and 38, which are first and second heating devices, are attached to the, respectively. As the temperature sensors 35 and 36, for example, cryogenic temperature sensors such as thermocouples and silicon diode sensors are used, and the measurement data is transmitted to the cryopump controller 32 via the control boxes 31.

As the heaters 37 and 38, sheath type heaters made of electric wires or the like covered with pipes or the like are used, and are controlled by the cryopump controller 32 via the control boxes 31.

The cryopump unit 1 is composed of the cryopump 10 and the valves 14 to 17 of the pipes 11 to 13. The cryopump controller 32 may be connected to a host computer 33. For example, in a factory line, when one set (six cryopumps 10) controlled by the cryopump controller 32 is arranged in plural sets, that is, when a plurality of cryopump controllers 32 are provided, The host computer 33 may be provided, for example, in a case where the respective sets are collectively controlled.

In this embodiment, the host computer 33 or the cryopump controller 32 is operated to drive each compressor 20 and the cryopump unit 1 via each control box 31. The cryopump controller 32 controls the temperatures of the cooling units 52 and 53 according to the type of gas adsorbed in the cryopump 10. In particular,
The set temperature is input to each control box 31, and the temperature measured by each of the temperature sensors 35 and 36 is compared with the set temperature, and the heaters 37 and 38 are operated or stopped as appropriate, so that each of the heaters 37 and 38 is stopped. The temperature of the cooling units 52 and 53 is controlled.

Since the cryopump 10 may have a different heat load on the refrigeration unit 51 or a cryopump 10 that has been cooled down from a regenerating state (room temperature), the cooling units 52 and 53 may be different. Each control box 31 is individually provided so that the temperature of each cryopump 10 can be controlled.

According to this embodiment, the following effects can be obtained. 1) The temperatures of the first and second stage cooling units 52 and 53 in each cryopump 10 are measured by the first and second temperature sensors 3.
The temperature of the cooling units 52 and 53 is controlled to a predetermined temperature by controlling the first and second heaters 37 and 38 based on the measured temperatures.
Can be prevented from being cooled more than necessary, the consumption of helium gas as the refrigerant gas (working gas) of the refrigeration unit 51 can be reduced, energy can be saved, and the operating cost can be reduced.

2) Further, by controlling the temperature of each of the cooling sections 52 and 53 of each cryopump 10, the consumption (flow rate) of helium gas can be suppressed. Even if three (for example, three) cryopumps 10 are connected, the minimum necessary helium gas can be supplied to each cryopump 10. Thereby, the flow rate of the helium gas can be reduced, and the differential pressure between the high pressure side and the low pressure side of the compressor 20 can be sufficiently secured,
One compressor 20 and multiple cryopumps 10
, Each cryopump 10 can obtain sufficient cooling performance.

3) Each cooling section 5 of each cryopump 10
Since the temperatures of the cryopumps 2 and 53 are controlled using the heaters 37 and 38, even when the heat loads of the cryopumps 10 are different, the cooling unit 5 of the cryopump 10 with a small heat load is used.
The temperatures of the cryopumps 2 and 53 can be prevented from being unilaterally lowered, and the cryopumps 10 can sufficiently exhibit cooling performance.

4) Cryopump 10 during cool down
Is present, the temperature of the cryopump 10 during other operations is not excessively reduced, so that a decrease in refrigeration performance can be suppressed and a cool down time can be reduced.

5) Since each control box 31 is provided corresponding to each cryopump 10, even when the type of each cryopump 10 is different, control can be performed by associating the control box 31 with the cryopump 10, and the cryopump 10 can be controlled. Since a common pump controller 32 can be used, a highly expandable system can be provided.

6) Furthermore, since the cryopump controller 32 can be connected to the host computer 33 for control, when a plurality of cryopump controllers 32 are arranged in a factory, they can be collectively monitored and controlled. Furthermore, even when factories and management departments in various locations are located apart from each other, or when requesting management work to an external maintenance company, the cryopump controller 32 and the host computer 33 are connected via a communication line or the like. By doing so, remote management control can be performed.

It should be noted that the present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and also includes the following modifications.
For example, in the embodiment, three cryopumps 10 are connected to one compressor 20.
One or two, or even four or more cryopumps 10 may be connected to one compressor 20,
These may be appropriately set in consideration of the capacity of the compressor 20 and the like.

The cryopump controller 32 may be connected directly to each cryopump 10 without the control box 31 for control. Further, the number of cryopumps 10 controlled by one cryopump controller 32 is not limited to six in the above embodiment, but may be 1 to 5
Or seven or more. The number of controlled objects may be appropriately set according to the capacity of the cryopump controller 32, the arrangement state of the cryopump 10, and the like.

Further, in the above embodiment, the refrigeration unit 51 is a GM cycle refrigerator, but the present invention can also be applied to a modified Solvay cycle refrigerator or a cryopump employing a pulse tube refrigerator.

[0051]

According to the cryopump operation control method and operation control apparatus of the present invention, the temperatures of the first and second stages of the cooling units are measured and the temperatures of the respective cooling units are set to the predetermined temperature. , It is possible to prevent each cooling unit from being cooled more than necessary, to reduce the consumption of refrigerant gas (working gas), to save energy, and to reduce the operating cost.

Further, the flow rate of the refrigerant gas (working gas) can be suppressed by controlling the temperature of each cooling section of each cryopump to prevent the temperature of the cooling section from unnecessarily lowering. Therefore, even when a plurality of cryopumps are connected to one compressor, sufficient cooling performance can be obtained with each cryopump.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a cryopump operation control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing details of an operation control device of the cryopump of the embodiment.

FIG. 3 is an overall perspective view, partially broken away, showing the cryopump of the embodiment.

FIG. 4 is a sectional view showing a main part of the cryopump of the embodiment.

FIG. 5 is a diagram showing a flow rate characteristic of a compressor in a cryopump.

[Explanation of symbols]

 Reference Signs List 1 cryopump unit 10 cryopump 11 to 13 piping 14 to 17 valve 18, 19 pressure gauge 20 compressor 21, 22 piping 30 operation control device 31 control box 32 cryopump controller 33 host computer 35 first temperature sensor 36 second Temperature sensor 37 Heater as first heating device 38 Heater as second heating device 51 Refrigeration unit 52 First stage cooling unit 53 Second stage cooling unit 60 Radiation shield 61 Baffle 62 Cold panel 64 Vacuum chamber

Claims (6)

[Claims] 1. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An operation control method, wherein a first heating device and a first temperature sensor are provided in the first stage cooling unit, and a second heating device and a second temperature sensor are provided in the second stage cooling unit. The temperature of the cooling unit of the first stage and the second stage is measured by each of the temperature sensors, and the measured temperature and a set temperature set according to the type of supply gas supplied to the cryopump are provided. An operation control method for a cryopump, wherein each of the heating devices is operated based on the difference to control the temperature of each cooling unit. 2. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An operation control method, wherein a plurality of the cryopumps are provided, and a first and second heating device, a first and a second heating device are provided in the cooling units of the first and second stages of the plurality of cryopumps. A second temperature sensor is provided, and a refrigerant gas is supplied from a single gas supply device to the plurality of cryopumps, and the temperatures of the first-stage and second-stage cooling units of each of the cryopumps are adjusted. Measured by the temperature sensor, the measured temperature,
Operating each of the heating devices based on a difference from a set temperature set according to a type of supply gas supplied to the cryopump, and controlling a temperature of each cooling unit, wherein an operation control of the cryopump is performed. Method. 3. The cryopump operation control method according to claim 2, wherein the temperatures of the first-stage cooling units of the respective cryopumps are controlled to be equal to each other, and the second-stage cooling units of the respective cryopumps are controlled. Controlling the operation of the cryopump, wherein the temperatures of the cryopumps are controlled to be equal to each other. 4. The operation control method for a cryopump according to claim 1, wherein the second stage cooling section is operated at a temperature of 14 to 18K. Control method. 5. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An operation control device, comprising: first and second heating devices provided in the first-stage and second-stage cooling units, respectively; and a second heating device provided in the first-stage and second-stage cooling units, respectively. First and second temperature sensors, and the temperatures of the first-stage and second-stage cooling units are measured by the temperature sensor, and are set according to the measured temperatures and the type of supply gas supplied to the cryopump. A control unit for controlling the temperature of each cooling unit by operating each of the heating devices based on a difference from the set temperature. 6. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An operation control device, wherein a plurality of the cryopumps are provided, and a gas supply device that supplies a refrigerant gas to the plurality of cryopumps is provided. First and second heating devices provided in two-stage cooling units, first and second temperature sensors provided in the first-stage and second-stage cooling units, respectively, and each of the cryopumps A control unit for controlling the temperature of the first-stage cooling unit and controlling the temperature of the second-stage cooling unit of each of the cryopumps.