Cryopump Regeneration Control With Panel Temperature Sensing
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Solution Overview
Problem
Cryopumps face challenges in efficiently regenerating while minimizing the number of temperature sensors to reduce manufacturing costs and shorten heating times, as existing methods either require many sensors for uniform heating or prolong regeneration time.
Innovation Solution
A cryopump design with a refrigerator having two stages, a cryopanel with two panels cooled by these stages, and a control unit that uses stage temperature sensors for vacuum pumping and panel temperature sensors exclusively for regeneration, allowing for efficient heating process completion based on panel temperature measurements without additional heaters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensors are mounted on both the refrigerator stage and the cryopanel to monitor heating during regeneration, then the heating process can be accurately controlled, but the number of sensors increases and manufacturing cost increases
Solution Approach 1:
The patent extracts the temperature measurement function for regeneration control from the stage temperature sensor and assigns it exclusively to the panel temperature sensor. This separation allows the stage temperature sensor to focus on vacuum pumping control while the panel temperature sensor handles regeneration monitoring, reducing the need for multiple sensors to perform overlapping functions.
Solution Approach 2:
The panel temperature sensor is designed to serve multiple purposes: it monitors the cryopanel temperature during both vacuum pumping operations and regeneration heating processes. This multi-functional approach eliminates the need for separate sensors for each operation, reducing overall sensor count while maintaining measurement accuracy.
2Stability of the object's composition
If multiple temperature sensors are used to monitor uniform heating of the cryopanel during regeneration, then heating uniformity can be ensured, but the regeneration time is prolonged due to extended monitoring and heating duration
Solution Approach 1:
The patent implements feedback control using the panel temperature sensor to monitor cryopanel temperature during regeneration. The control unit continuously receives temperature data and adjusts the heating process accordingly, ensuring uniform heating while preventing unnecessary extension of regeneration time through real-time monitoring and adaptive control.
Solution Approach 2:
The system performs preliminary monitoring of the cryopanel temperature during the heating process using the panel temperature sensor. By anticipating temperature changes and adjusting heating parameters in advance, the system ensures uniform heating completion without requiring excessive heating time or multiple sensors for extended monitoring.
3Device complexity
If the stage temperature sensor is used to monitor cryopanel temperature during regeneration, then fewer sensors are needed, but the temperature measurement accuracy for panel heating control is insufficient
Solution Approach 1:
The patent segments the temperature measurement responsibilities by assigning different sensors to different measurement tasks. The panel temperature sensor is specifically positioned to measure cryopanel temperature, providing accurate local measurement for heating control, while the stage temperature sensor monitors refrigerator stage temperature for vacuum pumping operations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enables effective management of cryopumps with a minimal number of sensors, accurately determining heating completion and reducing regeneration time while protecting the refrigerator from overheating.
Implementation Method 1
A cryopump is a vacuum pump that traps gas molecules by condensing or adsorbing them on cryopanels cooled to an ultra cold temperature
Implementation Method 2
A cryopump is a vacuum pump that traps gas molecules by condensing or adsorbing them on cryopanels cooled to an ultra cold temperature
Implementation Method 3
regeneration including a heating process of the cryopanel
Data Source
AI summary
A cryopump includes: a first panel to be cooled by a first stage of a refrigerator; a second panel to be cooled by a second stage of the refrigerator; a panel temperature sensor provided with the first panel and/or the second panel; a stage temperature sensor provided with the first stage and/or the second stage; and a control unit that controls vacuum pumping based on the temperature measured by the stage temperature sensor. The control unit controls regeneration including a heating process of a cryopanel, and uses the temperature measured by the panel temperature sensor exclusively in the regeneration. The control unit completes the heating process based on the temperature measured by the panel temperature sensor.