Presentation on theme: "Final Report Viren Bhanot. Work Done Rotary compressor – Its working and calculations Small Experiment Line Bypass Heater Calibration Heat Balance Report."— Presentation transcript:
Final Report Viren Bhanot
Work Done Rotary compressor – Its working and calculations Small Experiment Line Bypass Heater Calibration Heat Balance Report Accumulator Dry-Out testing Accumulator Cooling Power measurements CMS Pixel Upgrade Users Manual for Building 158
Rotary Compressor Sanyo Compressor Model no.: C-C140L5 Dedicated for CO 2 Two-Stage compression Pressure rating of 90 bar (outlet, 2 nd stage)
Matlab Compressor Calculations
Small Experiment Line 250W Cartridge Heater Swagelok Fittings Concentric Heat Exchanger after Mass Flow Meter Actuators for Metering Valves
Heater Selection 250 W heater required Cartridge, insertion heater for direct heating Inlet to heater perpendicular to its length Flow development analysed for selection Hydrodynamic and Thermodynamic flow development Low watt density required
Heater Selection Correlations Used: Hausen Stephan Shah/London Flow Development Fully Developed Thermodynamically developing, Hydrodynamically developed Simultaneously developing
Heater Selection Specifications: Watlow Firerod Cartridge Heater Ф -3/8, Length – 7 Power W Watt Density – 5 W/cm 2 4 No-heat zone Epoxy Seals to protect from moisture
Swagelok Fittings Heater mounted on reducer union Inlet through Welding Tee fitting Tube inner dia = 1/2, heater dia = 3/8 Line between mass flow meter and metering valve in a concentric internal heat exchanger. Whole Assembly Welded Together
Actuator Electrical Actuator for Swagelok metering valves Two companies discovered: Hanbay inc. (Canada) Grotec (Germany) Actuator ordered from Hanbay (cost ~ $1500)
Bypass Heater Calibration Bypass Heater (2 kW) performance not satisfactory Virtually no heating at low powers, then sudden overheating at medium-high powers Output power not equal to power requested through PVSS Heater controlled through phase angle controller (inexpensive way of controlling heater) Span setting of heater too narrow. Corrected.
Bypass Heater Calibration Tests performed to measure heater power and compare it against input power (through PVSS) System run in single phase to measure enthalpy using Pressure and Temperature. Power o/p = Enthalpy Change x Massflow Rate Pressure, temperature measured across internal heat exchanger. Output power found to be not equal to input power
Bypass Heater Calibration
Phase Angle Controller chops up the sine-wave signal (4-20 mA) linear with time, instead of linear with output power Mustapha prepared MATLAB and PVSS programs to correctly calculate output power to match input power. New logic incorporated into PVSS by Lukasz. Works perfectly, and has been tested.
Heat Balance Heater Calibration tests expanded to give overview of heat balance for entire system. Heat addition/extraction measured to get an idea of system performance Compressor data also included Parameters measured P req Q pump Q heater Q in Q cond Q comp
Conclusions drawn: Up until 1100W, the readings are reliable. Readings above 1100W are unreliable due to premature boiling of CO 2 inside the tubes. Offset between requested power and power measured is due to heat added by the pump and surroundings. Compressor cooling capacity is lower than expected (this data is already 2 months old)
Accumulator Dry-Out Testing Accumulator heater in thermo-syphon configuration During start-up, accumulator heated for long time At higher vapor pressure, higher vapor density. At higher density, lower convective currents Risk of dry-out, heater melting.
Accumulator Dry-Out Testing
S. No. Heater Power Dry-Out Saturation Temperature (°C) 1250N/A Conclusions drawn: At 250W Heater Power, dry- out is not witnessed. Higher the heater power, lower the saturation temperature at which dry-out occurs. Some unexplained bumps are observed at higher powers, through sudden, steep rises and falls in the values of Thermal Resistance
Accumulator Cooling Power Tests done to measure cooling power in accumulator It was expected that cooling at 100% valve opening should match heating at 100% heater power (1 kW) This was not the case Some cooling power lost because cooling spiral passes through liquid CO 2.
Accumulator Cooling Power Accumulator cooled and then heated at specific rates. For example, 50% CV1105 valve opening corresponds to 50% heater power, 500W Slopes of cooling and heating measured. Cooling slope observed to be less than heating slope. Since slope unequal, this method not enough to determine cooling power
Accumulator Cooling Power
Rough estimate obtained by plotting Heaters power versus the value dp/dt (change in pressure per unit time) dp/dt values of cooling spiral superimposed on heating graph. This gives rough but useful estimate of cooling capacity.
Accumulator Cooling Power Cooling Power Measured: Valve Opening Cooling Power 25%60 50%225 75% %740
Accumulator Cooling Power Conclusions: Cooling power does not correspond to its respective heating power. The maximum cooling power available is only 740W. The cooling power at 25% valve opening is not a quarter of the full cooling power. This is due to the inertia of the fluid. Cooling Power is not completely linear over the entire range.
CMS Pixel Upgrade CMS Pixel layout being discussed with various iterations proposed. Latest proposal (at that time) was simulated to measure the fluid temperature and pressure drop. Results were compared with Barts results (with his global calculator) Joaos calculator was used in Matlab, and simulations with Friedel and Chisholm correlations. The simulation results were similar to, but not exactly the same as Barts own simulations.
CMS Pixel Upgrade
Users Manual The eventual aim of project was to prepare User Manual to allow external researchers (Belle, SLAC, IBL) to use the system without distracting Bart, Lukasz or Joao! The manual is about 60 pages long and will hopefully be used by someone in the future.