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THERMAL STABILITY & THE NANO HUTCH. ISDD - Thermal Stability Working Group R. Baker. THERMAL STABILITY &THE NANO HUTCH. Consequences of thermal instability (reminder) Experimental results (reminder) Design solutions Materials Limits Athermal design Environmental solutions
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THERMAL STABILITY&THE NANO HUTCH ISDD - Thermal Stability Working Group R. Baker
THERMAL STABILITY &THE NANO HUTCH • Consequences of thermal instability (reminder) • Experimental results (reminder) • Design solutions • Materials • Limits • Athermal design • Environmental solutions • Experimental hutch evolution • The Nano hutch study • Numerical model of the existing hutch • Improvement studies • The advantages of “phase change materials” • Conclusion & recommendations Thermal Stability & the Nano Hutch – R. Baker – March 2010
24 Hours +/- 0.5° C Consequences of thermal instability Typical standard ESRF hutch • What are the consequences ? Temperature (°C) Time (hours) Thermal Stability & the Nano Hutch – R. Baker – March 2010
Beam axis (into page) Sample stage 400mm Granite block 1400mm 1000mm Symmetry around beam axis Consequences of thermal instability For 1 K (+/- 0.5K) temperature change: 1000mm of granite ≈ 8.5μm 400mm of steel & aluminium ≈ 8μm TOTAL ≈ 16.5μm Floor Thermal Stability & the Nano Hutch – R. Baker – March 2010
Area Heat capacity Volume Film coefficient Consequences of thermal instability Thermal time constantτ= C.V / h.A Granite Volume ≈ 3 x 106 cm3 Area ≈ 130 x 103 cm2 Mass ≈ 8100 kg • Approximate thermal time constant : • Forced air flow (8m/min): 2 hours • Natural convection: 11 hours Thermal Stability & the Nano Hutch – R. Baker – March 2010
Consequences of thermal instability Typical Sample Mechanics 50 % Aluminium, 50% Steel Approximate thermal time constant : • Forced air flow (8m/min): 40 mins • Natural convection: 3 hours Volume ≈ 20 x 103 cm3 Area ≈ 8 x 103 cm2 Mass ≈ 120 kg Thermal Stability & the Nano Hutch – R. Baker – March 2010
Time constant on components – volume / surface τaV / A Consequences of thermal instability Approx. time constant : • Forced air flow : 40 mins • Natural convection: 3 hours Manufacturing process reduces V and increases A Volume ≈ 1000cm3 Area ≈ 600 cm2 Volume ≈ 282cm3 Area ≈ 1720 cm2 • Approx. time constant : • Forced air flow : 70 secs • Natural convection: 6 mins Thermal Stability & the Nano Hutch – R. Baker – March 2010
+/- 0.1 C 24 Hours 2h 6h +/- 0.35 C +/- 0.5° C Consequences of thermal instability Hutch Sample mechanics Granite • Can cause distortion, compound displacements and unpredictable behaviour. Temperature (°C) Time (hours) Thermal Stability & the Nano Hutch – R. Baker – March 2010
Temp. opto mechanics in box ID22 EH2 Hutch Temperature Experimental results ID22 EH2 Offset time : 3 hours. Opto mechanics is insensitive to high frequency variation in hutch temperature. Thermal Stability & the Nano Hutch – R. Baker – March 2010
Experimental results Hutch Temperature • For 0.5K temperature change : • 15µm vertical beam displacement • Combination of linear and angular drift • Beam position relatively insensitive to high frequency variations in hutch temperature ID23 Vertical beam position Thermal Stability & the Nano Hutch – R. Baker – March 2010
Design Solutions – Choice of materials • Cost ! • Low CTE = poor engineering properties. • “Standard” materials = high CTE. • Incompatibility with commercial products. • Gradients & local heat sources require high diffusivity…. • …..but also a stable environment. Thermal Stability & the Nano Hutch – R. Baker – March 2010
Thermal insulation enclosure Solid invar bars Incidence jack Support Axis Mirror Bender High stability Invar support Design Solutions - Limits Horizontally reflecting KB mirror assembly • Invar where possible • 5 µrad / °C • All Invar except mirror • No microjack or flexible axes • 2.6 µrad / °C Thermal Stability & the Nano Hutch – R. Baker – March 2010 12
Hutch Temperature Material # 1 e.g. Aluminium α = 23 x 10-6 Material # 1 e.g. Steel α = 12 x 10-6 H2 H1 For H Ref constant at Δ T : α M1 x H1 = α M2 x H2 and Reference Position H Ref τMaterial 1≈τMaterial 2 Floor Design Solutions - Athermal Design (simple model) Design solution insensitive to thermal drift using common materials Thermal Stability & the Nano Hutch – R. Baker – March 2010
Motor (heat source) Screw Guide Body Nut Moving tip Original – Stainless Steel body Original – Invar body Athermal design – Stainless Steel body Design Solutions - Athermal Design in practice Possible on simple mechanical assemblies ESRF Microjack Clamp Thermal expansion (µm) with holding current ESRF Microjack µm Time (mins) Thermal Stability & the Nano Hutch – R. Baker – March 2010
Environmental Solutions – Hutch Evolution Non insulated walls & ceiling Thermal leaks Standard air conditionning unit Plain doors – no SAS Standard hutch Principal function : User comfort Thermal Stability & the Nano Hutch – R. Baker – March 2010
Environmental Solutions – Experimental Hutch Evolution Walls lined with laminated chipboard – higher inertia Porous ducts – air renewal rate : 20 vols. / hour SAS Standard hutch Raised floor with multiple extraction grids ID 22 NI Hutch - vast improvement over the standard hutch – thermal stability improved by a factor of 5 Improved higher stability design Thermal Stability & the Nano Hutch – R. Baker – March 2010
Side granite +X, -Y Side granite +Y Side granite -Y Side granite +X, +Y Top granite Above sample in air 4 x PT100’s on KB mechanics Environmental Solutions – Temperatures • 24h cycle = 0.1 – 0.3°C • Gradient = 1°C • 24h cycle still present • Local heat sources ? • Still work to do on local shielding… Thermal Stability & the Nano Hutch – R. Baker – March 2010
The Nano Hutch study – “can we improve on what exists ?” The Nano hutch study - SEMIcad • Expertise in thermal stability & air flow simulation. Thermal Stability & the Nano Hutch – R. Baker – March 2010
The Nano Hutch study • Numerical model of the existing hutch • Data collection • Identified drawbacks • Existing configuration - stationary study • Existing configuration - transient study • Improvement studies • Improved configuration #1 • Comparison existing / improved configuration #1 • Improved configuration #2 • Improved configuration #3 • Improved configuration #4 Thermal Stability & the Nano Hutch – R. Baker – March 2010
Sensor positions Nano Hutch Study – Numerical Model of the Existing Hutch Data collection – thermistors calibrated to +/- 0.005°C against primary standards • 2 x RBR Loggers : • 16 x temperatures • Atmospheric pressure • Human presence • Hutch door state • Lighting state • Hot water valve state • Cold water valve state • Lakeshore logger : • 4 x KB temperatures All data logged to ESRF Historical Database Thermal Stability & the Nano Hutch – R. Baker – March 2010
Electrical power logger Sleeve 1 Sleeve 2 Position Velocity (m/s) Sleeve 1 Velocity (m/s) Sleeve 2 0 à 1 m 0,20 0,15 1 à 2 m 0,45 0,20 2 à 3 m 0,60 0,35 3 à 4 m 0,55 0,27 4 à 5 m 0,65 0,49 5 à 6 m 0,65 0,66 6 à 6,75 m 0,64 0,63 Total (m3/h) 1 800 1 300 3 100 Nano Hutch Study – Numerical Model of the Existing Hutch Data collection – Electrical power & air throughput Thermal Stability & the Nano Hutch – R. Baker – March 2010
Walls in contact with EXPH – 9mm lead, 13mm laminatedchipboard Roof – 9mm lead Walls in contact with EH3 – 12mm lead, 13mm laminated chipboard Walls in contact with SAS – 9mm lead, 13mm laminated chipboard Walls in contact with CC – 9mm lead, 13mm laminated chipboard Hutch door – 9mm lead Nano Hutch Study – Numerical Model of the Existing Hutch Data collection – Definition of thermal properties Thermal Stability & the Nano Hutch – R. Baker – March 2010
Electronics rack Mobile granite KB Monochromator Mobile electrical equipment Mobile equipment Main granite Mobile heat source Shutter Sample granite Nano Hutch Study – Numerical Model of the Existing Hutch Thermal Stability & the Nano Hutch – R. Baker – March 2010 23
Losses through chicanes Position of temperature control sensors Summer / winter temperature stability Numerical model of the existing hutch Identified drawbacks Thermal Stability & the Nano Hutch – R. Baker – March 2010 24
Chicane 1 Chicane 2 Chicane 6 Chicane 3 Chicane 5 Chicane 4 Identified problems – losses through chicanes =35% of total flow Thermal Stability & the Nano Hutch – R. Baker – March 2010 25
New air in from EXPH Identified problems – air conditioning principle (simplified) EXP hall Air conditioning unit Experimental hutch The goal : clean, thermally stable air Losses through chicanes Gradients & thermal instability Sensor unit Raised floor EXPH floor Thermal exchange with EXPH floor Thermal Stability & the Nano Hutch – R. Baker – March 2010 26
35 EXPH winter temp.+/- 0.5⁰C Outside summer temp.+/- 9⁰C 30 25 20 Temperature (°C) 15 10 5 Outside winter temp.+/- 5⁰C EXPH summer temp.+/- 1.5⁰C 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (days) Outside EXPH Winter temp. +/- 0.5⁰C Winter temp.+/- 5⁰C Summer temp.+/- 9⁰C Summer temp. +/- 1.5⁰C Identified problems – Sensitivity of EXPH to outside temp. Summer & winter – 20 days Thermal Stability & the Nano Hutch – R. Baker – March 2010 27
27 26 25 EXPH summer temp. Temperature (°C) 24 EXPH winter temp. 23 22 21 1 2 3 4 5 6 7 Time (days) Summer temp. amplitude 7 days : 4⁰C Winter temp. amplitude 7 days : 1⁰C Identified problems – Sensitivity of EXPH to outside temp. Summer& winter – 7 days Thermal Stability & the Nano Hutch – R. Baker – March 2010 28
Existing Configuration – Stationary Study Air Speed Vertical section Thermal Stability & the Nano Hutch – R. Baker – March 2010
Air speed imbalance Thermal Stability & the Nano Hutch – R. Baker – March 2010
Almost all new air evacuated directly Thermal Stability & the Nano Hutch – R. Baker – March 2010
Existing Configuration – Stationary Study Air Speed Horizontal section Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Air deviated by mono Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Thermal Stability & the Nano Hutch – R. Baker – March 2010
0 0.5 1 Speed Uncontrolled zone Thermal Stability & the Nano Hutch – R. Baker – March 2010
Existing Configuration – Stationary Study Temperatures Vertical section Thermal Stability & the Nano Hutch – R. Baker – March 2010
Large vertical gradient Thermal Stability & the Nano Hutch – R. Baker – March 2010