Core Technology: Heat Exchangers - Carl Munters · PDF fileTitle: DOAS_Core-Heat_Exchangers Author: usroajepa Created Date: 10/14/2016 4:33:06 PM Keywords ()

Core Technology: Heat ExchangersMike Herwald

Regional Sales ManagerOctober 11, 2016

[email protected]

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Copyright 2015 Munters Corporation

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•Wheel Heat Exchangers

–Enthalpy

–Sensible

•Plate Heat Exchangers

–Counter-flow

–Cross-flow

•Heat Pipe Heat Exchangers

•Polymer Tubular Exchangers (EPX)

Air-to-Air Heat Exchangers


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3 or 4 Angstrom

Molecular Sieve

Rotary Wheel Heat Exchangers

Aluminum Matrix Rotary Exchanger


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Water vapor in supply air stream is

adsorbed on the desiccant

Because the vapor pressure in the colder exhaust air stream is lower than the water vapor pressure on the desiccant surface, the water is desorbed and exhausted back to the outside

Molecular sieve is a man made material with controlled pore openings to adsorb only certain type of vapors and gases.

4A pore opening

Molecular Sieve: How Does It Work?


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Performance of a 75% effective wheel (Sensible + Latent)


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The Total Energy Recovery Wheel Benefit

Control Point

Conditions Leaving Wheel

55°F DewPoint

75°F Temperature

Outside Weather Variations

Total energy recovery significantly reduces the variations in operating conditions.


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Honeycomb Matrix


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Brush Seals Limit Leakage


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Purge Minimizes Carryover

A portion of the outside air stream is used to flush out

the contaminated return air still contained in the flutes of the wheel.

Supply Air

Outside Air

Purge angleis dependent on

face velocity

Exhaust Air


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Plate Heat Exchangers - Counter-Flow Heat Exchanger

• The counter-flow heat exchanger provides

the maximum potential for energy transfer.

• Two 2-gas streams flow counter current to

one another facilitating a temperature

difference for the entire length of its flow

path. The longer the flow length in this

design the more effective the heat

exchanger becomes.

• Munters can achieve up to 85% effective

heat transfer with the counter flow design.

HOT GAS OUT

COLD GAS

IN

COLD GAS

OUT

HOT GAS

IN


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Counter-flow Plate

• Continuous- fold

• 60-85% effective

• Many Airflow Configurations

O/A

S/A

R/A

E/A

U-Flow

K-Flow L-Flow

X-Flow


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K-Flow Heat Exchanger

K-Flow


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Z-DUCT SERIES 85

WATER WASH


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Cross-Flow Heat Exchanger

• In practice, the cold air flows in a cross-

flow direction to the exhaust or hot flow.

Because the air streams move in

transverse 90° directions, the heat

exchanger is termed cross-flow. COLD GAS

IN

COLD GAS

OUT

HOT GAS

IN

HOT GAS OUT


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Cross-flow Sensible Plate

• Cross-flow has individual plates separated

by embossed dimples


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Counter flow Plate Heat Exchanger - 75% eff. sensible heat recovery


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HEAT EXCHANGER FROSTING


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2/12/2002

30.9 36.4 43.2 51.4

24.2 28.9 35.3 43.8

17.1 20.4 25.6 33.3

9 10.9 13.8 18.9

0/50% 0/50% 0/50% 0/50%

72/30%64.456.649.142.4

72/30%61.651.943.436.6 SAT

72/30%57.745.936.8 SAT32.3 SAT

72/30%51.237.531.2 SAT25.7 SAT

OUTSIDE AIR OUTLET (SUPPLY)

OUTSIDE AIR INLET

RE

TU

RN

AIR

IN

LET

EX

HA

US

T A

IR O

UT

LET

CROSS FLOW HEAT EXCHANGER STUDY

"COLD CORNER"

34°F


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2/12/2002

30.9 36.4 43.2 51.4

24.2 28.9 35.3 43.8

17.1 20.4 25.6 33.3

9 10.9 13.8 18.9

0/50% 0/50% 0/50% 0/50%

72/30%64.456.649.142.4

72/30%61.651.943.436.6 SAT

72/30%57.745.936.8 SAT32.3 SAT

72/30%51.237.531.2 SAT25.7 SAT

OUTSIDE AIR OUTLET (SUPPLY)

OUTSIDE AIR INLET

RETU

RN A

IR IN

LET

EXHA

UST

AIR

OUT

LET

CROSS FLOW HEAT EXCHANGER STUDY

"COLD CORNER"

1. Bypass

2. Coldest Air on Coldest Day


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Counterflow HX

O/A

S/A E/A

0°F

70°F

24°F 50°F

What about Frost?


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Traversing Defrost Prevents Ice

WORM GEAR DRIVE ROD

TRAVERSING PLATE (~5in/min)

DRIVE MOTOR

END VIEW

SA/OA VIEW

SA RA

OA EA

TRAVERSING PLATE BLOCKS COLD OA PASSAGES ALLOWING WARM RA TO

MELT ANY FROST BUILD-UP


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• Gives MAX use of Heat

Exchanger in winter

Traversing Defrost


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Thermo-Z High Temperature HX


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Thermo-T High Temperature HX


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Heat Pipe Heat Exchangers


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Heat Pipe Heat Exchanger

HOT

COLD

Refrigerant

Liquid evaporates this end

Vapor condenses this end

55% eff in Summer and Winter


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• Each Heat Pipe has a Mechanical Fitting

Allowing for Retrofit with Future

Refrigerant Enhancements


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Heat Pipe Heat Exchanger - 55% eff. sensible heat recovery


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When there is no return air to recover building energy, Wringer can use wrap-around heat pipe,

straight heat pipe, or plate heat exchanger.

HX 1 HX 2 95/78

73/72 50/50 72/59


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Wrap Around Heat Pipe


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Wringer provides free pre-cool and re-heat


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Heat Exchanger Comparison

PLATE HEAT PIPE WHEELNOMINAL SENSIBLE EFFECTIVENESS 68% 58% 75%NOMINAL LATENT EFFECTIVENESS 0% 0% 75%

MOVING PARTS NO NO YESMAINTENANCE REQUIREMENTS MINIMAL MINIMAL HIGHPARTICULATE PASSAGE EXCELLENT GOOD NOT GOOD

LEAKAGE NONE NONE 5% - 20%

CLEANABILITY EXCELLENT GOOD NOT GOOD

SIZE LARGE COMPACT VERY COMPACT

LIFE EXPECTANCY 25 YRS + 25 YRS + 10 YRS +

COSTAbout same as heat pipe / wheel

About same as plate / wheel

About same as plate / heat pipe


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Questions


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Core Technology: Heat Exchangers - Carl Munters · PDF fileTitle: DOAS_Core-Heat_Exchangers Author: usroajepa Created Date: 10/14/2016 4:33:06 PM Keywords ()