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Heat Exchanger Support Bracket Design Calculations

Description: This engineering note documents the design of the heat exchanger support brackets. The heat exchanger is roughly 40 feet long, 22 inches in diameter and weighs 6750 pounds. It will be mounted on two identical support brackets that are anchored to a concrete wall. The design calculations were done for one bracket supporting the full weight of the heat exchanger, rounded up to 6800 pounds. The design follows the American Institute of Steel Construction (AISC) Manual of steel construction, Eighth edition. All calculated stresses and loads on welds were below allowables.
Date: January 12, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Commissioning Test Results for D-Zero's Helium Refrigerator

Description: The test objectives are: (1) Make liquid helium and measure refrigerator capacity; (2) Measure liquid helium dewar heat leak, transfer line heat leak, and liquid nitrogen consumption rates; (3) Operate all cryogenic transfer lines; (4) Get some running time on all components; (5) Debug mechanical components, instrumentation, DMACs user interface, tune loops, and otherwise shake out any problems; (6) Get some operating time in to get familiar with system behavior; (7) Revise and/or improve operating procedures to actual practice; and (8) Identify areas for future improvement. D-Zero's stand alone helium refrigerator (STAR) liquified helium at a rate of 114 L/hr. This is consistent with other STAR installations. Refrigeration capacity was not measured due to lack of a calibrated heat load. Measured heat leaks were within design values. The helium dewar loss was measured at 2 to 4 watts or 9% per day, the solenoid and VLPC helium transfer lines had a heat leak of about 20 watts each. The liquid nitrogen consumption rates of the mobile purifier, STAR, and LN2 subcooler were measured at 20 gph, 20 to 64 gph, and 3 gph respectively. All cryogenic transfer lines including the solenoid and visible light photon counter (VLPC) transfer lines were cooled to their cryogenic operating temperatures. This included independent cooling of nitrogen shields and liquid helium components. No major problems were observed. The system ran quite well. Many problems were identified and corrected as they came up. Areas for improvement were noted and will be implemented in the future. The instrumentation and control system operated commendably during the test. The commissioning test run was a worthwhile and successful venture.
Date: June 30, 1997
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Gas Helium Storage Tank Pressure Vessel Engineering Note

Description: This is to certify that Beaird Industries, Inc. has done a white metal blast per SSPC-SP5 as required per specifications on the vessel internal. Following the blast, a black light inspection was performed by Beaird Quality Control personnel to assure that all debris, grease, etc. was removed and interior was clean prior to closing vessel for helium test.
Date: November 11, 1996
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Helium and LN2 Storage Requirements for D-Zero Upgrade

Description: Calculations were done to determine a recommended size for the liquid helium storage dewar, gas helium storage tanks, and liquid nitrogen dewar requirements. I recommend a Liquid helium storage dewar with a nominal size of at least 2500 liters (660 gallons), preferably 3000 liters (792 gallons). I recommend obtaining gas helium storage tanks with a maximum allowable working pressure (MA WP) of 250 psig or greater. Combined volume to be at least 5880 cubic feet (44,000 gallons). I recommend obtaining a second liquid nitrogen dewar at D-Zero, dedicated to the refrigerator, solenoid and VLPC systems. The ideal dewar would have a volume of around 16,000 gallons. It's MAWP needs to be greater than 55 psig.
Date: April 4, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Liquid & Gas Nitrogen Line Sizing for D-Zero Upgrade

Description: This engineering note documents the calculations done to properly size the liquid/gas nitrogen piping system for the D-Zero refrigerator, solenoid, and VLPC upgrade. See the line sketch of the system on the next page. The sketch shows the chosen line sizes, estimated lengths of piping runs, estimated steady state flow rates and pressure drops for each pipe section. The raw calculations are attached as an appendix. The estimated steady state flow rates were developed in D-Zero EN-421, 'Helium and LN2 Storage Requirements for the D-Zero Upgrade'. The pressure drop calculations take into account the two phase property of the fluid on the inlet piping. The outlet piping is sized for saturated vapor. These calculations supplement sizing that was done in D-Zero EN-416, rev. 6/26/95, 'Pipe Sizing for Solenoid/VLPC Cryogenic Systems', EN-416 only looked at the Solenoid and VLPC sections of the system. In a previous EN-430, 'LN2 control valve sizing', a calculation was done to address the cool down flow rate necessary. The minimum cooldown flow rate needed for a simultaneous, serial cooldown of the refrigerator, solenoid and VLPC system was 6.4 g/s. This warm flow would get choked by an opening less than 0.175-inch in diameter. All the piping/tubing sizes exceed this size, so cooldown will not be a problem. The available pressure drop for the VLPC and solenoid control valves was calculated to be 5.5 psid and 27 psid respectively. The actual delta P is expected to be larger because the conservativeness of using maximum flow rates and fluid properties that yield pressure drops on the high side.
Date: September 14, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Liquid Nitrogen Valve Sizing for D-Zero Upgrade

Description: There were 5 control valves and 2 manual valves for the liquid nitrogen distribution system that needed to be sized and procured for the upgrade. This engineering note documents the calculations done to properly size these valves. A table summarizes the valve choices. The raw calculations are attached as an appendix. The calculations jump around a bit. No effort was made to re-organize or rewrite them for the reader. The sizing calcs. on Pages 1 through 4 were first pass calcs. based on pure liquid to the valves with no attention to flashing/choking. The calcs on pages 5 through 8 then refine the calculations by considering the LN2 to the valve inlets to be two phase with quality of 0.032. This is a real situation if the LN2 subcooler is out of service for use as a He cooldown heat exchanger. Also, flashing would occur for this situation and is taken into account. The end result of this refinement pushed the Cv values up by about a factor of 3 over the initial calcs. of pages 1 through 4. The results of the refined (correct) calculations pages 5 through 8 appear in the table above. The required operating Cv's are smaller than commercially available LN2 control valves. Therefore it has been decided to use Fermilab Saver type control valve assemblies with the valve bullet Cv1s listed above. The bullets are 100: 1 equal percentage types and provide better control at the lower percentage of valve Cv values. See flow characteristic data and curve for these valves in appendix B. The manual valves will be commercially purchased, probably a Cryolab model CV3-84-5WPG2 or CV8-84-5WPG2 or CVI model V-1060-050-VJ. Pages 8-10 calculate a minimum required cooldown flowrate as referenced in Cryogenic Systems by Barron. This was done to be sure the valves ...
Date: September 13, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Lower Cleanroom Roof Quick Load Analysis

Description: This engineering note documents calculations done to determine the margin of safety for the lower clean room roof. The analysis was done to give me a feeling of what the loads, stresses and capacity of the roof is prior to installation and installation work to be done for the helium refrigerator upgrade. The result of this quick look showed that the calculated loads produce stress values and loads at about half the allowables. Based on this result, I do not think that special precautions above personal judgement are required for the installation work.
Date: November 17, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Summary of Warm-Up After Draining for the D-Zero LAr Calorimeters

Description: After a very successful physics run, the D-Zero detector Liquid Argon Calorimeters were drained in preparation of the detector rollout. During the roll out process, the calorimeters were without cooling. Information regarding the temperatures, estimated heat transfer, and pressure maintenance are documented in this engineering note.
Date: March 14, 1996
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Cryogenic and Safety Considerations for Moving the South End Cap Calorimeter to the Sidewalk

Description: The south end cap calorimeter (ECS) will need to be moved off of the detector platform to allow for the installation of new central tracking components. This engineering note documents the cryogenic and safety issues associated with the planned move. Because of the difficulty involved in building a temporary vent line out of the building, we plan to vent the ECS condenser flow, 6 scfm N2 into the assembly hall atmosphere. Information contained herein proves that this is safe even for failure/relief conditions. The details regarding the cryogenic and safety aspects of the ECS move have been thought out and planned. The cryogenic operation of the ECS calorimeter will be limited to maintaining it's pressure by keeping it cold and isolated while it is in it's temporary position off the platform. The 4 gph liquid nitrogen flow required for this operation is easily absorbed into the DZero assembly building atmosphere without any safety concerns. Emergency or failure scenarios have been addressed on a conservative basis and also pose little threat. Other safety features built into the system such as the liquid nitrogen excess flow switch, vent line liquid sensor, and monitored ODH heads provide additional assurance that an unexpected hazard would be identified and contained.
Date: September 25, 1996
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Cryogenic Line Routing: Refrigerator to VLPC Cryostats & Solenoid

Description: This engineering note documents the proposed cryogenic line routing from the liquid helium (LHe) refrigeration plant to the detector solenoid and VLPC cryostats. Many figures are included to aid in understanding the route. As an appendix, I include some general comments relevant to the topic. Also listed are a number of routing options that were considered before the proposed route was finalized.
Date: October 4, 1994
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: D-Zero Assembly Hall ODH Analysis

Description: The ODH analysis presented here covers the high bay and assembly hall docking area of the for the D-Zero detector. It includes the STand Alone helium Refrigerator (STAR) in the building. It also includes the D-Zero detector and it's associated cryogenic and gas systems. An ODH analysis is presented which shows that the D-Zero assembly building high bay including the detector docking area is ODH class O. Probabilities, leak rates, and fatality factors are generated for all items that are sources of inert gas. The scope of analysis included the calorimeter and gas components on the detector, the helium refrigerator/liquifier components, and the future solenoid and visible light photon counter cryogenics that will be added to the D-Zero detector. The analysis demonstrates that the calorimeter and helium refrigerator systems pose no ODH hazard to personnel.
Date: March 12, 1997
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Calc. to Determine Need for a N2 Phase Separator

Description: A nitrogen phase separator is recommended on the liquid supply line at the helium refrigerator plant. This engineering note documents the calculations done to reach that conclusion. The steady state liquid nitrogen consumption rate for the refrigerator, VLPC and solenoid systems is about 30 gal/hr. The estimated heat leak for the piping run to the refrigerator location is 50 watts. The calculated quality at the refrigerator was 0.032. Given this quality, a two phase flow model based on Lockhart-Martinelli and also incorporating Baker diagram nomenclature was run on TK solver. The result of this program was that without the use of a phase separator we could expect a slug flow pattern with a volume fraction of gas of 65%. Based on this, I recommend that we use a phase separator to siphon off the gas before the nitrogen is sent to a standard saver type subcooler. Including the phase separator will help ensure proper operation of the subcooler. The subcooler will help us attempt to deliver single phase liquid to the nitrogen control valves.
Date: April 7, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Transfer Line Branch Considerations for Solenoid & VLPC

Description: The transfer line for the solenoid currently has a dead branch on it. Issues regarding the solenoid transfer line also apply to the VLPC transfer line. Issues that need to be addressed are: (1) What is the heat load on the branch? (2) Would it be a good idea to run the LN2 radiation shield on the branch? (3) What are the thermal acoustic oscillation parameters of a dead headed branch? A simple remedy, although not analyzed was to install a jumper with a flow restriction at the end of the helium piping to allow a small flow to pass from supply to return. Thus eliminating a stagnant gas volume in which pressure pulses would develop. (4) Do we need to have a vapor trap to keep liquid from sloshing back and forth from the cold end to the warm end? (5) Comment: The tee that passes the 2-phase return into the nested LHe supply/return pipe should be pointed up so that the volume of transfer line acts sort of like a phase separator full of liquid. It is very difficult to predict the behavior of the dead ended branch. Therefore the conservative thing to do is to keep the Branch cold as in option A. Use a valve inside the bayonet box for the LHe. Due to space constraints, use a valve and u-tube arrangement for the LN2. The additional heat leak from keeping the section cold is very reasonable. The heat load to LHe is 0.8 W or 2.3 W and to LN2 is 13 W or 71 W when the detector is run in the collision hall or assembly hall respectively. To prevent thermal acoustic oscillation from occurring in the dead ended female bayonets, we can install male bayonet vacuum plugs. The heat load to the system ...
Date: June 16, 1995
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: West End Assembly Hall Platform Design Calculations

Description: This engineering note documents design calculations done for the bayonet feed can platform installed at the far west end of the assembly hall. The platform is mounted off of a cast concrete wall directly south of where the shielding block wall is stacked. A summary of the loading, reaction forces and stresses is shown on the page 3. As can be seen, the calculated stresses are very small, maximum value = 2540 psi. The material used is structural steel tubing, ASTM A500 Gr. B, with a minimum yield strength of 46 ksi and minimum ultimate tensile strength of 58 ksi. The reaction forces for the upper two members will be carried together by a 1/2-inch mounting plate. The mounting plate is attached to the wall by four 1/2-inch Hilti wedge anchors. The allowables for each wedge anchor are 2400 lbs. tensile, 1960 lbs. shear. The major reaction load for the top members is a combined 3627 lbs. tensile load which can easily be handled by the four bolt pattern. Some small moment reactions not listed on the summary page add negligible (400 lbs.) force couples to the axial loading. The bottom members are also attached to a mounting plate that is bolted to the wall. See page 15 for Hilti wedge anchor data.
Date: January 3, 1996
Creator: Rucinski, Russ
Partner: UNT Libraries Government Documents Department

D0 Silicon Upgrade: Pipe Sizing for Solenoid / VLPC Cryogenic Systems

Description: The addition of a solenoid magnet and VLPC detectors are two of a number of upgrades which will occur at the D-Zero detector in the near future. Both of these upgrades will require cryogenic services for their operation. The purpose of this engineering note is to document the pipe/tube size choices made for these cryogenic services. This was done by calculating the required flow rates to cool down the magnet and VLPC's over a reasonable length of time and to determine the required piping sizes for a given allowable pressure drop. The pressure drops for steady state conditions also are addressed. The cool down requirements drove the pipe size decision. The raw engineering calculations that were done for this project are included as an appendix to this note. The body of this document discusses the methods and results of the calculations. As a quick summary, Figures 1 and 2 show the size selections. Tables 1 and 2 give a more detailed size and description of each section of Solenoid and VLPC transfer line.
Date: February 20, 1995
Creator: Rucinski, Russ & Sakla, Steve
Partner: UNT Libraries Government Documents Department