P16452: Active Reciprocating Compressor Valve Assembly Week 9: Subsystem Design Review

Agenda Project Summary Updated Documentations Subsystems Concepts Vessel Inlet Valve Inlet Regulator Suction Valve Active Valve Active Valve Assembly - Engineering Requirements Active Valve Assembly - Morph Chart Active Valve Assembly - Pugh Chart Controls Risk Assessment Future Plans

Project Summary Background and Current State Compressors have valves that are passive devices that work with a spring. These valves experience high plate impact velocities which causes fatigue failures Therefore valves have short operating life that leads to frequent replacement Problem Statement Design, build, and test an active compressor valve assembly Goals and Benefits Goal of this project is to design and build an active reciprocating compressor valve assembly that controls when to release air from the compressor The test facility should simulate compression cycle. Significant gains on efficiency and wear are possible if valves are actively controlled Demonstration will require instrumentation to prove the design is meeting reciprocating compressor like specifications. Constraints End result must budget $5,000 Shop air will be needed to provide pressure to the cylinder Labview must be used to collect relevant data

Selected System Level Concept Shop air is regulated to 5 psi, then flows through a binary valve into the vessel Once vessel reaches 5 psi, exit valve opens and air is discharged to atmosphere. Exit valve closes. Suction valve opens and tank pressure reaches atmosphere. Cycle repeats

Updated Documentations - CR Customer Requirement #ImportanceDescriptionComments/Status CR11Valves opening and closing are actively controlledVery Important CR21Test facility simulates compression cycle CR31Active valves assembly is interchangeable with passive valve assembly CR41Valves open and close simultaneously CR51Logs data in an easy to read format CR61Compatible with LabView CR71Valves seat firmly against housing when closed CR81Test bench is constructed to avoid user injury CR92Demonstration system behaves similarly to the ESH-1 compressor CR102Valve opens and closes at a rate of 6 Hz CR113Discharge vessel provides back pressure CR123Active valve system conclusively performs better than passive spring CR133Able to see components in use during demonstration

Vessel Based on system level design: Inlet Regulator: Pressure Regulator Inlet Valve: On/Off Binary Valve Suction Valve: On/Off Binary Valve Need to figure out: what size is the vessel how to attach suction valve to vessel where to install pressure sensor

Controls National Instruments USB-6212 BNC Analog I/O Resolution16 bits Voltage Range-10V - 10V Update Rate250 kS/s

Active Valve Assembly - ER

Active Valve Assembly - Morph Chart

Concept #1 - Solenoids ●Coil around each valve ●Ferromagnetic poppet ●Applying current to the coil will induce a magnetic field, moving the poppet up or down based on the direction of the current and proportional to the magnitude

Concept #2 - Assisted Piezo Piezo actuators offer very little displacement; we will somehow have to compensate for this in our design. a.Gearboxb.Lever

Concept #3 - Piezo with Many Poppets Rather than add unnecessary mechanical complications, another solution to the small displacement provided by piezo actuators is to simply add more poppets and pathways for air to travel, increasing the effective orifice size. These poppets can even be controlled by just one piezo device by actuating a plate with fingers rather than individual plugs.

Active Valve Assembly -Pugh Analysis Concept Selection Criteria: 1. Actively controlled 2. Fast response time 3. Cost 4. Safety 5. Low Impact Velocity. (Reduce/Eliminate Chattering) 6. Be similar to the current passive valve assembly.

Active Valve Assembly - Feasibility Piezo Actuator Valve Consideration: Preliminary Orifice Area: ~0.15 mm^2; Total “Piezo Poppets”: ~211

Con’t Solenoid Consideration: Wm = 0.5NLi^2; Energy Stored in One Solenoid Fe = dWm/dx; Electromagnetic Force in One Direction

Risk Assessment

Future Plans Vessel concept generation and selection Valve assembly Pugh chart Bill of materials Project plan for detailed design, final review, and MSD 2