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Refrigerant Inventory Calculation

Daniel DettmersAssociate Researcher

IRC

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Refrigerant Inventory Determination

What is the quantity of refrigerant in your system?

Vessels, piping, evaporators, condensers, compressors (oil separators), traps, etc.

How does that inventory change over time?Do I care? ?

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Refrigerant Inventory Determination

Required for ALL ammonia refrigeration systems

OSHA ComplianceTo establish whether or not it is a covered processAs part of Process Safety Information for covered processes

EPA ComplianceChemical Inventory ReportingOff-site consequence analyses

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Where is the best place to look for ammonia?

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Places to look for ammonia:

Cold liquid:low temperature recirculators (vessels)pumped liquid linesflooded evaporators (chillers and air-cooling evaporators – including surge drums)

Warm liquid:high-pressure receiverscontrolled pressure receiverscondensers, thermosiphon pilots, oil coolers

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Places to look for ammonia:

Two-phase:wet returnstransfer stationsevaporators – including DX & overfed evaps

Vapor?

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Next, Calculate Inventory

φθ

φ

⋅−=

⎟⎟⎠

⎞⎜⎜⎝

⎛ −=

21802

2sinD

HD

D/2H

θ

φ

( ) ( )36042 θπ ⋅= DApie

( ) ( ) ( )

tripiesectioncross

tri

AAA

HDHDDA

⋅−=

−⋅⎟⎠⎞⎜

⎝⎛ −−⋅=

− 2

22221 22

satsatsat

estpiperef

TdTT

ddM

⋅⋅−⋅−⋅+

⋅+⋅−=

16767.00002111.02142.0

0282.23353.3441.42

2,,

phasetworefpipepipephasetworef VM −− ⋅= ,,, ρ

⎟⎟⎠

⎞⎜⎜⎝

⎛−+=

− liquidvaporliquidphasetworef

xρρρρ

1111

,

( )insatrefoutletphasetworefref C ,,,, ρρρ +⋅= −

outletphasetworefoutletphasetworef v ,,

,,1

−− =ρ

refinternalevapevapref VM ρ⋅= ,,

( )inletliquidinletvaporinletliquidinletref

vvfv ,,,,

1−+=

ρ

( )( )evapliquidevapvapor

evapliquidpressurehigh

hhhh

f,,

,

−

−= −

[ ]mmBh

lbmmBhCapacityM mnominalcondenserref 90, ⋅≈

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Or, Use IRC’s Tools

Downloadable at:

http://www.irc.wisc.edu

Under “Software Tools”

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Alternatively, the IRC’s Charge Management Tool

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Charge Management Tool

Estimates refrigerant inventory in:Piping

Vessels: horizontal and vertical

Evaporators

Condensers

Compressors

Generates output formsForms can be Word files, HTML, or email attachments

Calculations grouped by equipment, location, or charge

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4vessel

partialdV Hπ= ⋅

dvessel

L

Hliquid

2

4vessel

totaldV Lπ= ⋅

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Infrastructure

Ammonia properties determined by EESTool is composed of four sections

Location & PreferencesInput CalculationsOutput FormsLoad & Save

Tool is accessible to IRC members under “Software Tools” on website

www.irc.wisc.edu

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Starting a new session…Location & Preferences

Input Calculations

Output Forms

Load & Save

Location & Preferences

Input Calculations

Output Forms

Load & SaveEach equipment piece can be organized into areas.Each equipment piece can be organized into areas.

To begin, click this arrowTo begin, click this arrow

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Input Calculations

Unassigned is a default area for all equipment.Unassigned is a default area for all equipment.

To add a charge calculation, select the equipment type from this drop down menu

To add a charge calculation, select the equipment type from this drop down menu

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Adding Equipment

Make sure to provide a thorough description of the equipment piece

Make sure to provide a thorough description of the equipment piece

To run the calculation, click “Calculate Charge”To run the calculation, click “Calculate Charge”

Each input value has an associated unit. Conversions are automatically performed.

Each input value has an associated unit. Conversions are automatically performed.

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Adding Equipment, cont.

To add a new area, click this link.

To add a new area, click this link.

The previous calculation now appears in this table.The previous calculation now appears in this table.

The green check indicates no errors were found. If there is an error, clicking on this icon will reveal any details.

The green check indicates no errors were found. If there is an error, clicking on this icon will reveal any details.

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Adding an Area

The name given here will appear in the area list under Input Calculations, below “Unassigned”

The name given here will appear in the area list under Input Calculations, below “Unassigned”

To continue, click the arrowTo continue, click the arrow

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Adding an Area, cont.To change any preferences, such as unit defaults or location information, click the following menu item.

To change any preferences, such as unit defaults or location information, click the following menu item.

Selecting an equipment type from this menu will add equipment to this area.

Selecting an equipment type from this menu will add equipment to this area.

The new area now appears in the list.The new area now appears in the list.

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Location & Preferences

If you change the elevation, any calculations where you input a gauge pressure will need to be recalculated.

If you change the elevation, any calculations where you input a gauge pressure will need to be recalculated.

To save your changes, click the arrow. Once you have saved your information, click a menu item above to perform additional calculations or generate output forms.

To save your changes, click the arrow. Once you have saved your information, click a menu item above to perform additional calculations or generate output forms.

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Output Forms

When generating an output form, several options are available, such as the form layout, document type, and the ability to send the form as an email attachment. To continue, click the arrow.

When generating an output form, several options are available, such as the form layout, document type, and the ability to send the form as an email attachment. To continue, click the arrow.

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Example Output Form

The total charge and equipment types have been tallied here. Subsequent pages of the form provide details for each area or equipment type (depending on what form layout was selected).

The total charge and equipment types have been tallied here. Subsequent pages of the form provide details for each area or equipment type (depending on what form layout was selected).

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Load & Save

To load an existing session (from your computer), click “Browse” and select it. Click the arrow to continue.

To load an existing session (from your computer), click “Browse” and select it. Click the arrow to continue.

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Example of a Loaded Session

There are three options that can be performed on each equipment piece:

- Delete

- Move to another area

- Make a copy

There are three options that can be performed on each equipment piece:

- Delete

- Move to another area

- Make a copy

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Closing Notes

This is a Beta versionPlease send us any bugs you find

EES (Engineering Equation Solver) is the computational engineEES cannot run simultaneously with itself

Too much traffic can freeze the EES program, preventing further calculationsIf this occurs, save your session and try again later

Contact the IRC with any questions/comments Info@irc.wisc.edu866-635-4721