Psychrometric Chamber Operation procedure
Procedure Process A. Pre-check A1. i) Wear safety glasses and remind others to wear them. Use hearing protection in the compressor room when the compressor is running and being in there for longer than 30 seconds. Check if another large power user is running (i.e. wind tunnel), in that case do not operate the rooms to prevent breaker failure. A2. Check the water, steam and air connections i) Make sure that water valves behind the compressor room to oil cooler and to the condenser are open. Check valves, condensing pressure regulator, condenser and oil cooler as well as the entire waterside plumbing for visible leaks. Use flashlight, as necessary. ii) Make sure that the green steam valve underneath the white insulating pipe, on the ceiling to the compressor room, is not leaking. Check the elbow as well as the ground below it for water. iii) Check for any liquid in the air dryer on the south (orange sight glass) and the north (transparent sight glass) sides of the room; if there is, relieve the water from the bottom of the containers by turning small black valve. Pressure indicated should be ranging from 15 to 20 psi for both circuits. Adjust as necessary. A3. Check the psychrometric chamber i) Perform a visual inspection of the rooms. Clean both rooms from cables and other unnecessary items. Check for spilled liquids or other fire hazards. Remove any loose material. Remove any additional hazards; report to the shop if not possible to remove a hazard. ii) The data acquisition system should be clean and free from any hazards. B. Pre-running B2. Check the compressor room: i) No oil, electrical cords or loose rags on the floor ii) Remove any loose equipment or items on any surface which vibrates due to the operation of the compressor. B3. Prepare the compressor room: i) Open the two oil pump valves under the compressor located behind and in front of the oil pump by turning them counterclockwise. Screw on the caps firmly afterwards. ii) Open the compressor controller and remove the HOLD tag. iii) Switch on the on circuit breaker #17 (compressor and fan) and #38 (controller PSU’s) on the panel next to Prof Groll’s office and close panel firmly.
10/31/2011 02c55595c632c96863dd7720bdb95934.doc Page 1 iv) Go to the compressor room and check if the exhaust fan is running on “high”. If not, switch it on. v) Check if the anti-recycling light of the compressor is on. If not, ask the shop to check what the problem is (after switching off circuit breaker #17). B4 Prepare the psychrometric chamber i) Switch on the communication switch box and nozzle power supply (silver plate) outside the psychrometric chamber. ii) Power switches both up to activate AHU3, AHU1 and AHU4; both down to activate AHU2, AHU1 and AHU4. See schematic at the left switch for details. iii) Switch on the dew point monitor, if needed for your experiment, since it needs several minutes to produce accurate readings. iv) Open VisSim in the computer outside the room with an existing file in the Desktop\Barreto\manual2008*.vsm. Use the most up to date version. v) Right click switches of the blowers AHU3, AHU4 and AHU1 or AHU1, AHU2 and AHU4 to switch them on. vi) Click the run button in the VisSim program. vii) Push the green button on the emergency stop panel between the psychrometric room doors. viii) Switch on the variable speed drive of the blower of AHU1 by pressing the local/remote button and then the run button to start it. ix) Physically check blower operation and airflow direction. x) Set the room temperatures in VisSim32. xi) Add some reheat and coils in VisSim32 with minimum 12 tons (or 9 tubes) of cooling for control in the operating AHUs. Make sure to only run coil/reheat/defrost after the blower for that AHU is working (based on the previous physical check). xii) Switch on the compressor in VisSim32. xiii) Specify a compressor setpoint evaporation temperature (from 10F to 20F); skip this step if you run the rooms in manual mode (standard). C. Operation C1 Compressor room i) Check for unusual oil leakage of oil pump. ii) Make sure that the “anti-recycling” light is off, turn the capacity adjustment knob to manual. iii) Switch on the compressor at the panel. iv) Make sure that the “sec. oilpump running” light is on.
10/31/2011 02c55595c632c96863dd7720bdb95934.doc Page 2 v) Watch the panel of the compressor outside the room and observe the capacity and temperatures of the compressors during initial start-up and the “sec.oilpump running” light should be off afterwards. vi) Adjust capacity switch little by little manually until it gets close to your requirement, always above 25%. If you don’t know your requirement, start with 50%. Watch the pressures for a minute outside the room. vii) Make sure the capacity switch is set to “Manual”. viii) Check the high pressure and low pressure of the compressor. They should be steady. Evaporating pressure around the set-point in VisSim32 if you want to use automatic mode. Evaporating pressure no lower than -20F, condensing pressure not higher than 100F//200PSIG. vix) Close the door of the compressor room and leave the light on while operating. C2 Psychrometric chamber i) Close the doors of the two psychrometric chamber and put up the “test in progress” sign. ii) Check to see if the compressor capacity is above 25% iii) Adjust the reheat in VisSim, if necessary. iv) Adjust the capacity to reach and meet the operating point. vi) Adjust humidity after set point temperature is reached.
D. Shut down D1 VisSim, compressor and emergency stop i) Set the humidity setpoint in VisSim32 of both rooms to be 100% for at least one minute ii) Set the humidity setpoint to zero in both rooms. iii) Go to the compressor room and decrease the capacity to below 30% little by little. iv) Wait for 30 seconds and shut down the compressor manually. Check that anti- recycling light comes on. v) In VisSim, in the following order, switch off any bypass/desuperheat setting, compressor, coils, reheat, defroster. Wait 30 seconds switching off the blowers. vi) Push the red button on the emergency panel between the doors of the psychrometric rooms. vii) Stop the VisSim program, then log off/lock computer, DO NOT shut down computer. D2 Other hardware i) Switch off the communication switch box and nozzle power supply.
10/31/2011 02c55595c632c96863dd7720bdb95934.doc Page 3 ii) Switch off the circuit breaker #38 in the panel next to Prof. Groll’s office, close panel firmly. iii) Switch off circuit breaker #17 at the panel next to Prof. Groll’s office, close panel firmly. If compressor room is above 85 F, leave door open. iv) Close the two valves for the oil pump in the compressor room and tighten the seals afterwards. Replace and tighten the cover of the first valve before starting on the second. v) Put the “HOLD” tag back vi) Make sure that the saturated discharge temperature of the compressor declines steadily and high pressure and low pressure equalize. vii) Make an entry to the Log Book of the psychrometric room about the date and duration of the operation.
Safety information: 1. Position of fire extinguisher One (ABC) at the entrance of the Hudelson room One (BC) near the panel of the circuit breakers One (BC) at the entrance of the psychrometric room One (ABC) between the dock door and the mailbox If unclear which material is burning, use ABC fire extinguishers. 2. Important Communications Contacts Emergency Phone 911 Building Deputy Bob Brown Professor in Charge Operating Student
4. Carry the hand-held phone located outside the Hudelson room when operating alone in the West Wing, so that you can call help in an emergency. 5. Always use extra reheat first and then cooling coils to adjust the temperature when the compressor loading is low. 6. Maintain the compressor capacity to be 25% or higher for all kinds of operation 7. Maintain HP (compressor discharge) below 200PSIG. If it goes above this value for an extended period of time, ask Frank to adjust the condensing pressure regulator. Stop the system immediately if the pressure exceeds 210 PSIG. 8. Emergency Stop: Push a red button on one of the 5 emergency stop panels.
10/31/2011 02c55595c632c96863dd7720bdb95934.doc Page 4