20 Possibilities to reduce energy consumption and CO2 ...media.firabcn.es/content/S036014/docs/20...

29.09.20141

Possibilities to reduce energy consumption and CO2‐emissions of paintshop‐dryers

EUROCAR‐Presentation

Dipl.‐Ing. Olaf Neese (CVET)Dipl.‐Ing. Karl‐Heinz Dammeyer (CVET)Dipl.‐Ing. Lukasz Piech (CVET)Prof. Dr.‐Ing. Otto Carlowitz (TU Clausthal)

29.09.20142

Outline

1. Introduction

2. Use of energy in paint dryer systems in the automotive industry

3. Basic approaches to adjust the heat‐balance in existing paint dryer systems with Thermal exhaust air purification plant (thermal post‐combustion; germ.: TNV)

4. Evaluation of the energy‐saving‐potential

5. Load‐controlled volume flow adjustment (germ. LAVA)

6. Prospect

29.09.20143

Basic possibilities to decrease the use of process energy

enhancement: permanent reduction of energy consumptionoptimization: the optimum of the use of energy is defined, known

and can be (almost) achieved

Reduction of energy use with

A organizational /logistic measures

B enhancement or optimization of current processes

C implementation of new processes

immediate short and medium term long term

1.Introduction

2.Use of energy

paint drying system

3.Heat balance approaches

4.Evaluation energy savings potential

5.LAVA

(volume flow adjustment)

6.Prospect

Outline

29.09.20144

Energy input of an automotive plant by main production steps

Observation:The paint shop has the highest energy demand

1.Introduction

2.Use of energy

paint drying system


4.Evaluation energysavings potential

5.LAVA


6.Prospect

Outline

29.09.20145

Paint shop carbonemissionsOutline

Question:Which possibilities are available to reduce the energy demand of already existing production lines?

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.20146

Simplified flow sheet of a top coat paint drying system (example)

Exhaust heat usage Exhaust air pre‐heater in the thermal post combustion (3) Infrared zones with mixing chambers (not in new plants) Convection zones with circulation gas recuperators (4) Fresh air pre‐heating with recuperator (5)

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.20147

Energy flow sheet of a top coat dryer in the dimensioned maximum load state

Energy demand only slightly variable, because of• TNV‐temperature has to be constant• Exhaust air (amount and temperature) constant• organic load in the exhaust air/gas low

TNV‐temperature: 750 °CExhaust air vol. flow: 10,000 m3/h load: 30 car bodies/h

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.20148

Causes of heat imbalances at dryer System

Nearly every dryer does not operate in its calculated maximum state

A. static imbalancetemperature of the clean gas at stack is permanently (too) high transmittance heat loss of the entire plant overestimated subsequent isolation addedmass of car bodies constantly smaller than dimensioned number of car bodies permanent smaller than dimensioned short heating times required (hence overdesigned)

B. dynamic imbalancetemperature of the clean gas at stack is temporarily (too) high production breaks and cleaning car bodies with significantly differing masses set up times errors in the operation procedure

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

Outline

29.09.20149

Identified options to adjust the heat balance of a dryer

1. Energetically separation of dryer heating and waste air cleaningPrecondition: the exhaust gas cleaning process has a

very low energy demand (RTO, catalytic RTO, biological processes,…)

2. Increase of the waste gas preheating in the thermal oxidizer

3. Reduction of the temperature level in the thermal oxidizerand complementation of a catalytic or in‐line RTO‐step

4. Reduction of the exhaust air volume flow rate (LAVA)and compensation of the changed flow conditions of the dryer

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

Outline

29.09.201410

1. Energetically separation of dryer heating and waste air cleaning

High investment costs if fitted subsequently

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

dryer

car bodies+SKID

solvent

freshair

freshair

fuel

parts

cleangas

(process)

cleangas

(RNV)

car bodies+SKID

29.09.201411

2. Increase of the waste gas pre‐heating in the TNV‐system

increase of V by 15 % from 60 % to 75 %: reduplication of the heat exchange area reduction of the fuel demand by approx. 40 %

heat exchange area

V

VWÜA

1

Abluftvorwärmgrad V

rela

tiver

Bre

nnst

offb

edar

f

Fläc

henv

erhä

ltnis

Wär

meü

bert

rage

r

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201412

3. Reduction of the TNV‐temperature leveland complementation of a catalytically step

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201413

4. Load controlled volume flowadjustment: LAVA

simultaneous reduction of waste and fresh air volume flow rate therefore smaller clean gas enthalpy flow and fuel demand caution: (limited) intervention in the flow balance of the dryer the solution was examined in detail within a research project

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201414

How to evaluate the savingspotential

Equipping the waste heat line and the TNV with temperature sensors (temperatures of waste air, clean air, circulation air and fresh air)

Affixing of pilot tubes to measure the volume flow rates Experimentally reduction of the waste air volume flow, measurement of the

resulting changes in the waste heat line Continuous recording of the measured data (approx. 14 days)

(temperatures, concentrations, volume flow rates) Derivation of the heat transfer characteristics from the dimensioning data

and measurement data, feeding in a mathematical model

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201415

Measurements to obtain the currentstate and implementation of LAVA

Outline

aim: obtaining the characteristically energy demand of the examined plant in different operational conditions

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201416

Measured clean gas temperatures in thewaste heat line of a top coat dryer

0

100

200

300

400

500

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

Messzeit

Tem

pera

tur [

°C]

T311_RG_W31ein T321_RG_W32ein T331_RG_W33ein T341_RG_W34einT351_RG_W35ein T361_RG_W36ein T365_RG_W36aus T201_AbL_TNVein

Lee

rlauf

Vol

llast

Mittlere Last (Produktionstag)

Auf

heiz

betr

ieb

16

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

idle state

full load

partial load state (production day)

time

tempe

rature

29.09.201417

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

Air balance and natural gas demand of a top coat dryer at full load state

per hour per yearDemand natural gas: 1070 kW 7490 MWCosts natural gas: 43 €/h 300 T€/a (0.04 €/kWh)CO2‐emissions: 257 kg/h 1800 t/a (0.24 kg/kWh)

production: 7000 h/a

load: 27 car bodies/hcirc. gas

circ. gas

circ. gas

circ. gas

waste air

waste air

clean gas

clean gas

fresh air

29.09.201418

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

Energy savings potential with LAVA is up to 20 % at full load state

operation effort/h saving/h saving/aDemand natural gas: 850 kW 220 kW 1540 MWCosts natural gas: 34 €/h 9 €/h 63,000 €/aCO2‐emissions: 204 kg/h 53 kg/h 371 t/a

production: 7000 h/aload: 27 car bodies/hcirc. gas

circ. gas

circ. gas

circ. gas

waste air

waste air

clean gas

clean gas

fresh air

29.09.201419

Calculated savings potential at full load (27 car bodies/h)

prediction: volume flow rate reduction: 7.800 m3N/h

natural gas demand : 850 kW (savings: 20,6 %)

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201420

waste air

waste air

clean gas

clean gas

fresh air

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

Air balance and natural gas demand of a top coat dryer at partial load state (70 %)

per hour per yearDemand natural gas: 1095 kW 7665 MWCosts natural gas: 44 €/h 308 T€/a (0,04 €/kWh)CO2‐Emission: 263 kg/h 1841 t/a (0,24 kg/kWh)


circ. gas

circ. gas

circ. gas

load: 20 car bodies/h

29.09.201421

Energy savings potential with LAVA is upto 35 % at partial load state

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

daily mean

operation effort/h saving/h saving/aDemand natural gas: 690 kW 405 kW 2835 MWCosts natural gas: 28 €/h 16 €/h 112.000 €/aCO2‐Emission: 166 kg/h 97 kg/h 679t/a

production: 7000 h/aload: 20 car bodies/h

recirculated

gas

circ. gas

circ. gas

circ. gas

circ. gas

waste air

waste air

clean gas

clean gas

fresh air

29.09.201422

Calculated savings potential atpartial load state (daily mean: 20 car bodies/h)



Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201423

waste air

waste air

clean gas

clean gas

fresh air

Air balance and natural gas demand of a top coat dryer at idle load state (0%)

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

per hour per yearDemand natural gas: 1150 kW 8050 MWCosts natural gas: 46 €/h 322 T€/a (0,04 €/kWh)CO2‐Emission: 276 kg/h 1932 t/a (0,24 kg/kWh)

production: 7000 h/a

load: 0 car bodies/hcirc. gas

circ. gas

circ. gas

circ. gas

29.09.201424

waste air

waste air

clean gas

clean gas

fresh air

Energy savings potential with LAVA is up to 59 % at idle load state

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

daily mean

operation effort/h saving/h saving/aDemand natural gas: 450 kW 700 kW 4900 MWCosts natural gas: 18 €/h 28 €/h 196.000 €/aCO2‐Emission: 108 kg/h 168 kg/h 1176 t/a


circ. gas

circ. gas

circ. gas

29.09.201425

Calculated savings potential atidle load state (0 car bodies/h)



Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201426

Volume flow rate reduction shown as energy flow sheet (partial load 70 %)

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

LAVA can reduce the energy loss of the clean gas by 70 %

29.09.201427

Volume flow rate reduction shown as energy flow sheet (partial load 70 %)

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

LAVA can reduce the energy loss of the clean gas by 70 %

29.09.201428

Elaborate process to realize a LAVA(volume flow adjustment)

LAVA realization Project steps

1. Actual state analysis Measurements to establish the current state Evaluation of the energy demand characteristic Savings potentials and commercial viability

2. Implementationof LAVA switchgear

Implementation of LAVA controller (PLC) and visualization Connection of additional measurement instrumentation

3. Implementationof fan switchgear

Implementation of frequency inverters for exhaust air, fresh air and circulation fans (replacement of fans, if necessary)

4. Upgrade of dryer's process equipment

Temperature, pressure and volume flow instrumentation Safety technology including LEL monitoring Adjustment of safety devices

5. Connection of signal to existing controller

Definition of interface ports Connection of dryer control signals Connection of LAVA and fans switchgears

6. Start‐up of LAVA system Identification of LAVA operating parameters Adjustment of control and safety functions

7. Follow‐up inspection and documentation

System test operation and validation documentation, training and handover

LAVA is realized during ongoing production!It requires only three single production‐free days (e.g. at weekends)

weeks

0

4

8

9

12

6

7

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201429

Visualizing the LAVA switch cabinet during operation

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201430

Savings with LAVA in the volume flow adjustment mode

natural gas demand

volume flow rate

electrical energy1)

Outline

1) related to waste air‐ and fresh air fans

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

29.09.201431

6. Summary and prospect Four options to adjust the heat balance have been discussed on current

paint drying systems energetically separation of dryer heating and waste gas purification enlargement of the waste air preheating of the TNV temperature reduction in the TNV followed by a catalyst (or in‐line‐RNV)

control of the waste air volume flow rate (dependent on the demanded heat)

the latter two options have been examined within R&D projects A lower temperature in the TNV is only useful for a static savings potential

(thermic inertia of the system) the lower temperature has to cover the full load state

reduction of waste air in TNV (and reduction of fresh air) can use the dynamical savings potential by constant temperatures and only few influences by thermal inertia has a greater savings potential as the static temperature setback

for implementation of the volume flow adjustment there is a cooperation between Crone Wärmetechnik GmbH and the CVET GmbH

4 LAVAS have been realized so far (during ongoing production)(ca. 2 years of operation experience without failures).

Outline

1.Introduction

2.Use of energy

paint drying system



5.LAVA


6.Prospect

20 Possibilities to reduce energy consumption and CO2 ...media.firabcn.es/content/S036014/docs/20...

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Transcript of 20 Possibilities to reduce energy consumption and CO2 ...media.firabcn.es/content/S036014/docs/20...