PROJECT 13632Process Control Flow Cart: Heat Exchange Temperature Control Loop

Amanda Doucett, Dan Sacchitella, Jay Moseley, Micah Bitz, Marc Farfaglia, Rebecca Davidson

Presentation Agenda

• Project Overview• Customer Needs• Specifications• Initial Design Decisions (MSD1)• Budget/Bill of Materials• Final Layout• Process Control Lab Plan• Results of Testing• Project Achievements• Current Project Status• Conclusion• Acknowledgments• Q&A

Project Overview

• The objective was to build a flow cart that would illustrate process control to future chemical engineering students here at RIT.

• There were three projects with similar objectives, though the means of teaching process control varied slightly between them.

• Our project (P13632) required that the process control system incorporate controls based on temperature feedback loops.

• Temperature changes used for process control were achieved through the use of a shell-and-tube heat exchanger.

Customer Requirements

• Design for safe operation• Design for use by three students during allotted lab time• Portable• Easily connected/disconnected for lab use• Robust design• Minimal maintenance requirements• Utilize a control loop based on temperature changes• Require control of heated process flow and cooling exchange flow

rates• Operate both manually and through process control programming in

Labview• Capable of manual and automatic data collection

Operating Requirements

• 120 VAC for Instruments and Controllers• 25 psi instrument air• 80 psi compressed air• Fluid viscosity between 1 cP and 10 cP• Process mass flow rate between 500 g/min and 1500 g/min• Temperature range for process effluent of 70 °F and 130 °F• Heating fluid flow (water) rate between 1 GPM and 4 GPM

Initial Design Decisions - Pugh Chart

Risk Assessment

ID Risk Item Effect Cause Like

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Seve

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Impo

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Action to Minimize Risk Owner

1

Customer Priority Changes Delay of project progression

Poor communication/ Uncertainty

2 2 4 Have weekly meetings with guide and keep both sides updated on project

Project Manager

2 Unreliable Suppliers

Disrupt our project budget plan, and delay design process.

Parts are not available through Kodak 1 2 2

Take initiative and request parts from Guide, and compile a list of what we have and what needs to be ordered Group

3 Skill Set

Alters design slightly, and will change list of parts that we need to order

Only one EE to develop controls, and rest of team members have little experience in that field 1 2 2

Group EE seeks feedback from EE department to make sure concepts are feasible EE

4 Team Dysfunction

Poor team chemistry will demotivate group and may cause delays in deliverables.

Differences in opinions/ concepts 1 1 1

Reach consensus on ideas/concepts to make sure everybody is on board Group

5 Unavailability May delay deliverables Poor communications/ Illness 2 1 2

Let group know if/ why you can’t attend meetings. Plan ahead. Individual

6 Poor Communication People may not know current tasks

Lack of motivation/communication with group members 1 1 1

Keep everyone updated on current goals/ ideas. Ask for progress ahead of the date when the deliverable are expected.

Project Manger

Detailed Physical Design (MSD1)

Piping and Instrumentation Diagram (P&ID)

Functional Block Diagram (Electrical)

Budget/Bill of Materials

Vendor Description Model/SeriesCost (EA) Quantity Total Cost

N/A Exergy Heat Exchanger Series 35   1 $- VWR Heating/Cooling Recirculating Water Bath     2 $- N/A I/P transducer $-Cole-Parmer NSF-Approved Turbine Flow Meter, 0.4 - 4 GPM, 3/8" NPT (Male) EW-98516-92 $98.00 1 $98.00 Cole-Parmer 0-60 psi Dual-Scale Gauge, Bottom Connection EW-68007-04 $67.00 1 $67.00 N/A Research Control Valve, 3-15 psig N/A   1 $- Lowe's Rubbermaid 550 lb. Capacity Cart N/A $129.98 1 $129.98 Lowe's Miscellaneous Parts N/A $89.67 1 $89.67 McMaster-Carr Aluminum Strut Channel, 10 ft length 3230T48 $46.16 3 $138.48 McMaster-Carr Single Channel Plastic End Caps 3312T56 $0.62 20 $12.40 McMaster-Carr Vibration Damping Strut Mount Clamps, Zinc-Chromate Steel, 1 1/2" OD 32625T61 $2.92 3 $8.76 McMaster-Carr Nuts for Strut Channel, Zinc Plated Steel, 10-24 Thread 3259T42 $3.93 20 $78.60  McMaster-Carr 3/8” OD PE Tubing (50 ft)  5181K31 $0.26 50 $13.00N/A ¼” OD tubing $0 10 $-McMaster-Carr Titanium Bolts, 1.5", 10-24 thread 94081A149 $4.73 20 $94.60 Sparkfun 20x4 Character LCD LCD-00256 $17.95 1 $17.95 Sparkfun Thermocouple Amplifier Chip AD595-AQ $17.95 2 $35.90 Digikey MSP430G2553 microcontroller 296-28430-1-ND $2.58 4 $10.32 Digikey Microchip Technology 10 bit dac chip MCP4812A0T $2.30 2 $4.60 Mouser 9 volt plug in adapter N/A $5.54 1 $5.54 Sparkfun on/ off switch N/A $0.50 1 $0.50 Sparkfun voltage regulator 5V N/A $1.25 1 $1.25 Sparkfun voltage regulator 3.3V N/A $1.95 1 $1.95 Sparkfun k type thermocouples SEN-00251 $13.95 2 $27.90 McMaster-Carr k type thermocouples 3856K912 $20.33 2 $40.66Zorotools Electrical Enclosure   $100.00 1 $100.00   Resistive Thermal Device   $- 2 $-

Total Project Cost

$977.06

Budget = $1500

Final Design Layout

Labview InterfaceIndividual Temperature Sensor

Data

Manual Gain Set

Manual Temperature Set Point

Proposed Student Lab

1: PID Control – Analyze the difference in a real system between • Proportional control• Proportional and Integral control• Proportional, integral, and differential control• Deliverables: Graphs showing process over time, Analysis of overshoot and how it

was minimized

2: Temperature sensors – Fit temperature data to the sensor equations• Tt=To+T1-To [1-e-tτ]• Deliverables: Which sensor responds to control best? RTD vs. Thermocouple 

Operability TestingTest ID Test Name Relevant

SpecificationRelevant Customer Need Description Critical Value Pass/Fail

T1 Leak Test Minimal Cleaning Robust Design

Ensure all connections are tight and no liquid leaks from the system

Pass/Value Pass

T2 Accuracy of Rotameter N/A Robust design

The measurement the flow meter outputs should be confirms by experimentally measuring a volume of fluid collected over a set time period

20% Pass, 8% discrepancy

T3 Temperature Sensor Accuracy N/A Robust Design

The temperature value the temperature sensors return will be confirmed by comparing the readout to known values

Pass/Fail Pass

T4 Optimize ΔT Temperature Control Teaching

Test heat exchange over a range of inlet temperatures for the hot and cold streams to optimize heat exchange settings

Change in hot stream 10°

15° in 30 minutes

T5 Labview Runthrough N/A Student Use

Full testing of all labview interfaces to ensure communication with the computer

Pass/ Fail Pass

T6 Lab Assignment Runthrough N/A Student Use

Full testing of lab assignments to confirm the time requirments and results

Pass/Fail  

Operating Specifications Chart

Parameter Customer Specification Status Description

Instrument Air 25 psi air Converter functions as specified

Compressed Air 80 psi air Supplied through the building

Process Viscosity 1-10 cP Water is used for both flow streams

Process Fluid Flow Range 500 g/min to 1500 g/min Process bath rate falls within that range

Exchange Fluid Flow Range 1 to 4 GPM Water bath limited to a max of 0.5 GPM

Process Temp. Range 70° F to 140° F Bath will operate between -4° F and 392° F

Exchange Temp. Range 70° F to 140° F Bath will operate between -4° F and 392° F

Status Key

Specification Met

Working exception to specification, will not negatively impact functionality

Needs to be addressed in order to function as required

Customer Requirements – Project AchievementsParameter Status Description

Safety

Hot fluid is contained in the inner tube of heat exchanger, Electrical components are all contained within a sealed electrical box

Portability

All aspects of the cart are contained on the cart or on another portable cart. The only location restriction is access to a computer

Used by 3 students for 3 lab sections

Lab assignment is enough work for 3 students over 3 days

Control Based on Heat Exchange Heat exchange flow systemMinimal Maintenance Only fluid used is water no cleaning necessary

Manual Control Valve position can be changed through an input in Labview

Status Key

Completed

Working exception to specification, will not negatively impact functionality

Needs to be addressed in order to function as required

Current Project Status

• The cart has all mechanical aspects assembled and they have been tested for operability and accuracy

• The electrical component has been designed and assembled. Testing has been performed to ensure correct communication with the cart

• A Labview interface has been created for use with the system that outputs all relevant data and allows user input

• A lab procedure exploring the effects of process control equations on the heat exchange system has been designed. It is expected to take 3 students 3 lab periods to complete.

• The thermocouples are not currently registering data correctly with the Labview interface, but their purpose is simply to provide more process transparency for the students and they are not necessary for the system to function fully. There is a plan in place to correct the malfunction before the end of the term.

Project EvaluationSuccesses:

• Functioning product• Educationally valuable

lab assignment to accompany the product

• Met or exceeded design specifications

• Stayed within budget• Overcame equipment

failures

Failures:

• The lack of a truly multidisciplinary group resulted in challenges with mechanical design

• Lack of spare parts• Uneven distribution of

work• Minor troubleshooting

required

Future Work• Develop a noise introduction method• Add more mechanical manual control• Integrate a digital flow sensor• Labview can be easily updated for future needs

We would like to thank…

…our faculty guide, Steve Possanza, for his guidance and support during this project, the Chemical Engineering Department for their guidance and support, the Multi-Disciplinary Senior Design group for their funding and support, and Kodak for their generous contributions.

Questions?