Energy saving through evaporating cooling in comfort and industrial applications

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Information about Energy saving through evaporating cooling in comfort and industrial...

Published on November 14, 2016

Author: CAREL_group


1. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Luigi  Nalini,  Speaker   Energy  saving  through  evapora7ng   cooling  in  comfort  and  industrial   applica7ons  

2. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Everybody  has  certainly  experienced  the  cooling  effect   caused  by  a  current  of  air  on  the  swea1ng  skin  or  on   wet   clothes,   as   well   as   the   perceived   lower   temperature   in   the   vicinity   of   waterfalls   where   microscopic  water  droplets  are  suspended  in  the  air.     Based   on   empirical   observa1ons,   even   without   knowing    its    basic    physical    principle,    humankind    has   Evapora7ve  cooling  has  been  used  by   humankind  since  50  centuries  ago!   used  since  from  the  third  millennium  B.C.  the  evapora1ve  cooling  to  mi1gate   the  temperature  of  spaces,  par1cularly  in  areas  with  a  hot  and  dry  climate.     Only   over   the   last   two   centuries,   scien1sts   have   studied   the   basics   of   thermodynamics  and  processes  related  to  the  exchange  of  sensible  and  latent   heat   and   found   the   theore1cal   principles   of   cooling   by   evapora1on   which,   however,  has  played  a  marginal  role  in  the  recent  past  due  to  the  extensive   use  of  mechanical  refrigera1on  systems.    

3. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     According  to  the  molecular  kine1c  theory,  as  any  element  water  assumes  the   solid,  liquid,  gaseous  state  in  func1on  of  the  internal  energy  of  molecules,  that   occurs  as  vibra1onal,  rota1onal,  transla1onal  mo1on  and    reciprocal  collisions.             Temperature  is  a  measure  of  the  average  internal  energy  and  therefore  the   higher  the  temperature,  the  greater  the  internal    energy  of  the  molecules.   Upon  an  energy  input,  liquid  water  molecules  increase  their  internal  energy.     Part   of   them   reaches   an   energy   level   sufficient   to   enter   in   the   evapora7on   process,  overcoming  the  aWrac1ve  forces  of  the  bulk  of  the  liquid,  passing  to   the  gaseous  state  (vapor)  and  spreading  in  the  available  space  around.   The  Water  Evapora7on  Process  

4. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     0   5   10   15   20   25   30   35   40   45   50   14000   12000   10000   8000   6000   4000   2000   0   temperature  -­‐  °C   Vapor  pressure  -­‐  Pa   SATURATION  PRESSURE  VPS    OF  WATER  vs  TEMPERATURE   The   diagram   shows   the   pressure   exerted   by   the   water   vapor   molecules   vs   temperature   just   above   the   surface   of  liquid  water.     In   this   condi1ons   water   vapor   is   in   equilibrium   with   its   condensed   state   and   therefore   that   pressure   is   said   Satura7on  Pressure  PVS.     Leaving   the   liquid   water   and   entering   into   the   atmosphere   the   vapor   molecules  must  «compete»  with  the  pressure  exerted  by  the  other  gases.   The   vapor   molecules,   due   to   their   kine1c   energy,   exert   over   the   con1guous   bodies   a   macroscopic   pressure   propor1onal   to   the   number   and   to   the   force   of   the   collisions.   As   well   as   the   internal   energy,   also   vapor   pressure   depends  on  temperature.     Water  Vapor  Pressure  

5. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     The   atmosphere,   a   mixture   of   dry   air   (i.e.:   permanent   gases   -­‐   such   as   N2,   O2,   Ar   -­‐   without   vapor)   and   vapor,   has   a   pressure   PATM  (around  1,033  bar  at  sea  level)  that  is   equal   to   the   sum   of   the   the   individual   pressure   of   the   several   gaseous   components.     According   to   the   gas   laws,   the   individual   pressure   of   any   gas   (called   also   par7al   pressure)  in  the  mixture    is    propor7onal    to   THE  ATMOSPHERE  IS  A  MIXTURE  OF  GASES   OVERALL  PRESSURE  =  101.325  Pa  @  SEA  LEVEL   NITROGEN   OXYGEN   ARGON   WATER  VAPOR   Of  course  the  maximum  quan1ty  is  got  when  the  vapor  par1al  pressure  equals   the  satura1on  pressure  PVS  ;  in  this  condi1on,  the  air  is  said  Saturated.     However,   differently   from   permanent   gases   (whose   rela1ve   percentage   is   stable)  water  vapor  concentra7on  varies  with  1me,  loca1on  and  weather.       its  volumetric  frac7on;  therefore  the  number  of  molecules  of  water  contained   in  the  air  is  propor1onal  to  the  vapor  par1al  pressure.       Vapor  in  the  Atmosphere  

6. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     The  ra1o  between  the  actual  pressure  PV   and   the   satura1on   pressure   PVS   at   the   same   temperature   is   defined   rela7ve   humidity  RH:     RH  =  PV  /  PVS                    [%]                            (1)     The  Vapour  Pressure  Deficit,  or  VPD,  is   the  difference  between  the  actual  water   vapor   pressure   and   the   satura1on   pressure:   it   indicates   the   maximum   capability  by  the  air  to  absorb  addi1onal   vapor  at  that  temperature.         The    formula      closely      appoxima1ng    the   VAPOR  PRESSURE  OF  WATER  vs  TEMPERATURE  AND  RH   0   1000   2000   3000   4000   5000   6000   0   5   10   15   20   25   30   35   40   temperature  -­‐  °C   Vapor  pressure  -­‐  Pa   10%   25   PVS  =  3170   PV  =  1270   VAPOR  PRESSURE     DEFICIT   ATMOSPHERIC  PRESSURE  (101,325  Pa)   When  the  content  of  vapor  in  the  atmosphere  is  not  enough  for  satura7on,   also  the  vapor  pressure  PV  is    lower  than  the  saturated  pressure  PVS.   saturated  vapor  pressure  Pvs  vs.  temperature  T  [°C]  between  0°C  and  80°C  is:     PVS  =  exp  (23,5771  -­‐  4042,9/(235,57  +  T))            [Pa]                                      (2)   Psychrometric  Expressions    1/2  

7. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     The  vapor  content  in  the  atmosphere  is  called  absolute  humidity  x,  expressed   as  mass  of  water  vapor  per  unit  mass  of  dry  air;  it  can  be  calculated  knowing   the  par1al  pressure  Pv  -­‐  func1on  of  temperature  -­‐  and  rela1ve  humidity:         x  =  0,622  *  PV/(PATM  –  PV)                      [kgv/kga]                                                    (3)     The   expression   (3)   shows   that,   at   a   certain   atmospheric   pressure,   absolute   humidity  x  is  func7on  exclusively  of  the  vapor  pressure  PV.     Another  important  parameter  of  humid  air  is  the  enthalpy  H,  i.e.  its  energy   thermal  content,  made  of  the  heat  contained  in  dry  air  and  the  internal  energy   of  vapor  molecules,  that  depends  on  temperature  and  on  absolute  humidity:        H  =  cpa  *  T  +  x  *  (r0  +  cpv  *  T)  =  1,005  *  T  +  x  *  (2501  +  1,9  *  T)          [kJ/kga]          (4)     where:     •  T  [°C]  =  temperature;     •  cpa,  cpv  [kJ/kg°C]=  specific  heat  of  dry  air  and  of  water  vapor;     •  r0  [kJ/kg]  =  latent  heat  of  water  at  0°C.       The  expressions  from  (1)  to  (4)  are  the  bases  of  psychrometric  chart,  i.e.  the   graph  of  the  thermodynamic  parameters  of  moist  air  at  a  constant  pressure.   Psychrometric  Expressions    2/2  

8. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Water  liquid  molecules  require  an  heat  input  to  increase  their  internal  energy   in  order  to  pass  to  vapor.     This  heat  can  be  given  by  an  external  source  (i.e.:  by  the  sun,  by  electricity  or   by  burning  a  fuel)  as  it  happens  normally  during  winter  humidifica1on.       Alterna1vely,  the  evapora1on  heat  can  be  supplied  by  the  air  itself  with  no   external  input:  the  molecules  that  evaporate  absorb  heat  from  the  en1re  air-­‐ liquid-­‐vapor  system  which  then  undergoes  a  temperature  decrease.   This  process  is  therefore  defined  adiaba7c  (i.e.  without  transfer  of  heat)  and   isenthalpic  because  the  heat  content  of  air  being  humidified  does  not  change.     Just  for  the  same  reason  this  process  is  defined  adiaba7c  cooling.     In  an  adiaba1c  cooler  an  air  stream   is   circulated   over   an   extended   water  surface  with  which  it  comes   into  close  contact.   Within   the   cooler   the   air   flow   causes  the  evapora1on  of  water.   Adiaba7c  Cooling    1/2   water       adiaba1c  cooler       ADIABATIC  COOLER  SCHEME   cooled   humid  air   @  temp.  T2  <  T1     entering   warm  air   @  temp.    T1    

9. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Isothermal  Humidifica1on     Adiaba1c  humidifica1on   Air  Hea1ng   Air  Cooling   Temperature   Enthalpy   Absolute  Humidity   Rela1ve  Humidity   0   5   10   15   20   25   30   0   5   10   15   20   25   30   35   40   30   15   10   5   0   25   20   20   100   70   80   90   60   30   40   50   DRY  BULB  TEMPERATURE  -­‐  °C   ABSOLUTE  HUMIDITY  –  g/kg   PATM  =  101.325  Pa   10%   Process   Trend   Psychrometric  Chart  and  Basic  Processes   ISENTHALPIC  LINES  

10. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Due   to   the   difference   between   the   vapor   pressure   over   the   water   surface   and   the   par1al  vapor  pressure  of  unsaturated  air,  the   evapora1on  of  water  will  take  place.     The   lowest   temperature   theore1cally   aWainable   corresponds   to   the   intersec1on   between  the  isoenthalpic  line,  followed  along   the  process,  and  the  satura1on  curve:  this  is   represented   by   the   black   arrow   in   the   graphic.   Along  the  process  un1l  the  satura1on:   •  the   Vapor   Pressure   Deficit   decreases   down  to  zero;   •  the  rela1ve  humidity  arrives  to  100%;   •  the   cooling   effect,   due   to   evapora1on,   reaches  the  maximum  value.       RH    [%]   100%   60%   40%   80%   20%   PVS  –  PV  [Pa]     4   2   6   0       Qsp  [J/kg  of  air]     10   5   15   0   20   saturation   Vapor  pressure     deficit   Air  rela7ve     humidity   Cooling     effect   ON  GOING  EVAPORATIVE  COOLING  PROCESS           20,6   25   30   35   40   15   10   5   0   Vapor  par7al  pressure  -­‐  kPa     absolute  humidity  –  gv/kga       38   1     2     0     0,5     2,5     1,5     water       evapora1ve  cooler       38°C   20%  RH     20,6  °C   100%  RH     Adiaba7c  Cooling    2/2  

11. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     However,   along   the   process,   the   temperature   and   the   vapor   pressure   differen1als  between  humid  air  and  water   sharply  decrease,  making  the  satura1on  of   leaving  air  hardly  achievable  in  prac1ce.     The   capacity   of   an   evapora1ve   cooler   to   approach   the   satura1on,   defined   as   Satura7on  Effec7veness  μe,  is:     μe  =  (T1  –  T2)/(T1  –  TWB)              [%]     DIRECT  SATURATION  EFFECTIVENESS   Dry  bulb  temp.  -­‐  °C   T1  T2  TWB   The   evapora1on   of   water   involves   a   simultaneous   transfer   of   heat   and   mass   (evapora1ng  molecules)  between  the  air  stream  and  the  liquid  surface.     •  The  heat  exchange  is  propor1onal  to  the  temperature  difference.   •  The   mass   exchange   (evapora1ng   water)   is   propor1onal   to   the   vapor   pressure  difference.   •  Their  rate  depend  linearly  on  the  interface  area  between  water  and  air.     In  direct  evapora1ve  coolers  μe  ranges  between  20-­‐30%  (typical  of  the   tabletop  equipment)  up  to  90%  and  more  for  large  high  performance  ducted   Direct  Satura7on  Effec7veness  

12. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     The   adiaba1c   evapora1on   process   is   very   efficient   because,   where   prac1cable,  produces  a  cooling  effect  with  no  energy  consump7on.     An   evapora1ve   cooler   designed   for   air   condi1oning   purposes   reduces   the   processed  air  temperature  but  increases  its  humidity  content;  this  should  be   considered  in  order  to  keep  the  hygrothermal  room  condi1ons  within  the   limits  required  for  each  applica1on.   Therefore  room  air  condi1oning  by  means  of  an   evapora1ve  cooler  is  not  viable  just  recircula7ng   internal   air   because   the   indoor   humidity   would   soon  approach  the  satura1on  condi1on.     Instead,   it   requires   the   introduc7on   of   outside   air  to  which  obviously  must  correspond  an  equal   rate  of  exhaust  air.     Evapora1ve   cooling   equipment   can   be   direct   or   indirect.     40%  RH  80%  RH   100%  RH  100%  RH   YES   NO   Adiaba7c  Cooling  Requires  Air  Changes  

13. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     GI   Total  air  flow  rate   Gvent   Min  fresh  air  flow   EC   Evapora1ve  cooler   CC   Cooling  coil   GO   Outside  air  flow   CD   Combined  dampers   PC   Pre-­‐hea1ng  coil   RC   Re-­‐hea1ng  coil   The   free   cooling   by   Direct   Evapora7ve   Cooling   (DEC)   is   got   cooling   (and   humidifying)   outdoor   air   and   introducing   it   straight   into   the   space:   this   is   therefore   viable   whenever   the   temperature   T2   of   the   outdoor   air   downstream  the  adiaba1c  cooler  is  lower  than  the  indoor  temperature  Tamb.   In  fact,  for  the  same  air  flow,  the  cooling  capacity  is  propor1onal  to  the  air   flow  rate  and  to  the  difference  (T2-­‐Tamb).   GI       GO       GI       CD   PC   EC   CC   RC   AHU  UNIT  WITH  DIRECT  ADIABATIC  COOLER  AND  MOTORIZED  DAMPERS  TO  ADJUST  THE  AIR  FLOW  RATES     T2Tamb Direct  Evapora7ve  Cooling   from   the   space   to   the   space   from   outdoor   to   outdoor  

14. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     GI   Total  air  flow  rate   Gvent   Min  fresh  air  flow   EC   Evapora1ve  cooler   HU   Humidifier   GO   Outside  air  flow   α   Ra1o  GO/GE   HE   Heat  exchanger   CC   Cooling  coil   GE   External  air  flow   CD   Combined  dampers   PC   Pre-­‐hea1ng  coil   RC   Re-­‐hea1ng  coil   GO  (=  r  *  GE);  TO;  HO       GE;  TE;  HE           GI       CD   PC   HU   CC   RC   GI-­‐GE       HE       GI  ≥  GE  ≥  Gvent       AC       GO  ;  TC;  HA       GE  ;  TX;  HX   GO  ;  TA;  HA   GI       AHU  UNIT  WITH  INDIRECT  ADIABATIC    COOLER  AND  MOTORIZED  DAMPERS  TO  ADJUST  THE  AIR  FLOW  RATES     The   Indirect   Evapora7ve   Cooling   (IEC)   occurs   by   cooling   air   in   an   adiaba1c   humidifica1on  process,  and  then  in  turn  using  the  same  air  to  reduce  –  via  a   heat  exchanger  –  the  temperature  of  a  second  stream  of  air,  whose  moisture   content  remains  unchanged.   Indirect  Evapora7ve  Cooling  

15. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Based  on  a  mass  transfer  process,  an  adiaba1c  cooler  should  have:   •  enough  air  velocity  to  create  a  sufficient  turbulence  and  the  removal  of   vapor  molecules  from  the  water  surface;   •  enough  interface  surface  between  cooled  air  and  evapora1ng  water.     There  are  two  basic  ways  to  expand  the  surface:   1)  by  using  a  solid  wet  media  with  an  extended  surface  that,  if  kept  wet,   act  as  a  vast  water-­‐air  interface  area;   2)  by  introducing  into  the  air  stream  water  in  the  form  of  minute  droplets   using  a  process  known  as  nebulisa7on,  pulverisa7on  or  atomisa7on.     Features  of  Most  Used  Adiaba7c  Coolers  

16. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     In  these  adiaba1c  humidifiers  the  air  is  passed  through   weWed   pads,   i.e.:   honeycomb   structures   of   resin-­‐ impregnated   cellulose   or   glass   fiber   offering   a   wide   interface  area.     The  pads,  placed  ver1cally,  are  kept  wet  by  a  water  flow   distributed  on  their  upper  edge.   Wet  Media  Humidifiers    1/2   In   ducted   HVAC   systems   wet   media   humidifiers  are  generally  placed  inside  of  air   handling   units;   the   wet   pad   is   made   using   modules.   This   makes   possible   to   adapt   the   front   surface   and   the   depth   of   the   wet   media     according  to  the  available  space,  the  air  flow   rate,   the   efficiency,   the   allowed   pressure   loss.  

17. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Only  part  of  the  water  drawn  from   a   boWom   tank   by   a   recircula1on   pump   and   distributed   onto   the   pads   evaporates   when   the   rest   is   recirculated.     The   evapora1on   process   increases   the   concentra1on   of   salts   which   may   build   up   on   the   surface,   forcing  to  clean  or  replace  the  pads   when  clogged.   Furthermore  they  should  be  periodically  controlled  because  the  presence  of  a   warm  water  recircula7on  poten7ally  promotes  a  risky  bacterial  growth.     Last  but  not  least,  the  air  side  pressure  drop  of  the  pads  requires  an  addi7onal   energy  consump7on  even  when  no  humidifica7on  is  needed.     Their   use,   widespread   for   the   limited   price,   should   be   carefully   evaluated   looking  also  at  the  opera1ng  costs,  some1mes  surprisingly  high.   Wet  Media  Humidifiers    2/2  

18. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     These   devices   are   equipped   with   a   volumetric   pump   which   pressurizes   the  water  to  values  between  70  and   100   bar   and   delivers   it   to   small   nozzles   that   produce   a   fine   mist   (droplets   of   10-­‐15   micron)   easily   absorbed  by  air  stream    because    the     surface  offered  by  1  liter  of  water  atomized  at  15  μm  is    as  high  as  400    m2.     PUMPING  STATION   ATOMIZING  NOZZLE   High  Pressure  Atomising  Systems    1/2   The   distribu1on   piping   network   that   supports   and   supplies   the   nozzles   is   posi1oned  in  an  air  duct  or  placed  directly  into  the  environment  to  humidify.       NOZZLE  RACK   SUSPENDED  TYPE  NOZZLE  RACK  IN  AHU  SECTION  

19. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     High  pressure  atomising  systems  may  reach  an  excellent  level  of  accuracy   (±  2%)  of  the  humidity  in  the  controlled  space  and  very  high  capaci1es   with  a  negligible  electric  consump1on  absorbed  by  the  pump  (<4  W  per   liter  of  sprayed  water).       Under  the  hygienic  aspect  they  are  not  cri1cal  because  do  not  promote   bacterial  growth;  infact:   §  in   the   case   of   direct   atomiza1on   into   the   environment,   the   sprayed   water  is  fully  absorbed  by  the  air;   §  in  ducted  systems  the  frac1on  not  evaporated  -­‐  usually  very  small  -­‐  is   drained  without  recircula1on.     The  use  of  demineralised  or  sweetened  water  is  recommended  to  prevent   clogging  of  the  nozzles.     High   pressure   atomising   systems   are   available   for   capacity   up   to   many   thousands  of  kg/h.   High  Pressure  Atomising  Systems    2/2  

20. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Ultrasonic  Humidifiers   STAND  ALONE  UNIT   SMALL  SIZE     UNIT   DUCTED  TYPE  UNIT   Ultrasonic   humidifiers   provide   an   extra   fine   atomiza1on  of  water  (≈  3  μm)  by  means  of  the  high-­‐ frequency   vibra1on   (close   to   1,7   Mhz)   of   a   piezoelectric  element  (or  more  than  one,  in  parallel);   the  absorp1on  of  vapor  is  immediate  due  to  the  wide   interface  surface  (2000  m2  offered  by  1  liter  of  water   atomized  at  3  μm).       Due   to   size   and   cost   they   are   convenient   for   small   and   medium   installa1ons  (0,5  to  15  kg/h).     The  use  of  demineralised  water  is  highly  recommended.     Best  ultrasonic  humidifiers  reach  excep1onal  levels  of  precision   (±  1%)  in  the  en1re  range  of  their  rated  capacity  and,  thanks  to   the   high   efficiency   of   absorp1on,   they   are   suitable   for   the   distribu1on  of  the  produced  mist  directly  into  the  room  as  well   as  in  ducted  systems.      

21. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     To  Conclude,  let  Us  Men7on  a   Few  Case  Studies  

22. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Evapora7ve  Cooling:  Datacenter  Applica7on   The  need:  humidity  control  and  evapora1ve  cooling   A  company  has  a  big  data  center  in  Middlesbrough  (Newcastle-­‐  UK).  It  has  more  than  180  global  data  centers   and  IT  service  companies.   Data  hall   Atomizing  nozzles   Hot  exhaust  air   to  data  centre   Coniugated     dampers  

23. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Internal  Views  

24. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Evapora7ve  Cooling:  Air  Cooled   Heat  Exchangers   In  aircooled  heat  exchangers  (i.e.:  condensers,  radiators,  etc.)  the  intake   air  is  adiaba1cally  cooled  to  improve  the  performance  in  hoWest  periods.   Water   may   be   sprayed   in   excess   in   order   to   wet   the   finned   coil   so   promo1ng  a  further  evapora1on  during  air  hea1ng  along  the  exchanger.  

25. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     COMPARATIVA ESTACIONES 4/09/06 0,00 10,00 20,00 30,00 40,00 50,00 60,00 70,00 80,00 90,00 12.30 13.00 13.30 14.00 14.30 15.00 15.30 16.00 16.30 17.00 17.30 18.00 18.30 19.00 19.30 20.00 20.30 21.00 21.30 22.00 22.30 23.00 23.30 HORA ºCY%HR Tª EXT. PEÑAG. Tª EXT. ILUST. Tª AMB. PEÑAG. Tª AMB. ILUST. Tª IMP. PEÑAG. Tª IMP. ILUST. HR EXT. PEÑAG. HR EXT. ILUST. HR AMB. PEÑAG. HR. AMB. ILUST. HR IMP. PEÑAG. HR IMP. ILUST. El ecpa S.L. Instalaciones y Control The   aim   of   this   solu1on   is   to   provide   more   comfort,   cooling   the   environment   using   water   as   a   “source   of   power”,   because   it’s   considerably  more  economic  than  tradi1onal  cooling  systems  (direct   expansion)  as  it  consumes  less  power.     Evapora7ve  Cooling:  Subway  Applica7on   Number  of  pla•orms:  2   Q   =   90,000   m3/h   for   each   pla•orm   (ven1la1on)   Outdoor  air  =  100%   Discharging  air  condi1ons:     27-­‐28°C/70-­‐80%  r.H.   Result:  In  the  period  15/july/2006  to  15  sept/2006,  the  temperature   in  this  sta1on  was  3.4°C  colder  than  in  other  comparable  sta1ons.   Peñagrande  subway  sta1on,  Madrid  

26. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Need:  efficiency  improvement    of   a  new  gas  turbine  for  produc1on   of  electricity   Petrochemical  complex   With  23  plants,    they  operate  400,000  barrels  per   day  of  crude  oil,  produce  18.4  million  tons  per   annum  (mpta)  of  petroleum-­‐based  products  and  2.4   mpta  of  ethylene  and  propylene-­‐based  deriva1ves   Evapora7ve  Cooling:  Industrial  Applica7on   Technical  note:       Cooling  the  combus1on  air  ingested   by  the  turbine       –  even  by  a  few  degrees  –  can   increase  power  output  substan1ally.         This  because  cooled  air  is  denser   and  therefore  gives  the  turbine     a  higher  mass-­‐flow  rate  and   pressure  ra1o,  resul1ng  in  increased     turbine  output  and  efficiency  –  as   much  as  1  %  per  degree  Celsius.     Varia1on  of  the  performance  of  a  gas   turbine  vs.  air  intake  temperature  

27. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     The  solu7on   Project  condi7ons:   Airflow  :  80.000  m3/h     From  43°C  and  20%  R.H.   Desired  25  °C  with  max  85%  R.H.   Total  Rack  Capacity  :  690  l/h   Turbine  Evapora7ve  Cooling  Diagram  

28. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Humidifica7on  in  a  Music  Hall  in  Athens   The  needs     1)   Control  humidity  level  during  all  seasons,  ie..  instruments  made  of   wood  are  the  most  affected  and  come  into  contact  with  non-­‐wood   pieces,  string  instruments  (guitars,  violins,  etc.).   2)   Changes  in  humidity  cause  the  detune  problems  to  singers,  during   a  performance.  Room  environment  must  be  at  show1me  condi1ons   before  musicians  being  warming  up.   The  solu7ons     Music  hall:     4  –  adiaba1c  mul1zone  Master  sta1on   10  –  adiaba1c  mul1zone  Slave  sta1on   14  –  distribu1or  rack   14  –  drop  separators     Library:   2  –  adiaba1c  mul1zone  Master  sta1on   6  –  adiaba1c  mul1zone  Slave  sta1on   8  –  distribu1or  rack   8  –  drop  separators   Greek  Na1onal  Opera,  Athens  

29. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     CAR  FACTORY       Humidifica1on  in  most  automo1ve  paint  booths   has   tradi1onally   been   accomplished   by   water   spray   coils   or   wet-­‐media   located   in   the   air   houses  serving  the  paint  booths.   The  needs     Desired  stable  paint  booth  condi1ons  at  65  to   75°F  &  65  to  75%rH.     The  pain1ng  booths  are  supplied  with   permanently  condi1oned  air  by  a  ducted   system.   Humidifica7on  in  Water-­‐Borne  Pain7ng  Booths   The  results:  the  system  has  operated  with  a   precision  previously  unknown  in  this  industry,   achieving   set   point   in   10   minutes   from   cold   startup.   From   the   actual   performance   graph,   from   a   cold  start,  the  system  comes  into  specifica1on   within  10    minutes  and  then  maintains  ±1°F   and  ±2%rH.     The  old,  simple  cardboard  pads  will  no  longer   provide   the   precision   and   reliability   demanded.  

30. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Humidifica7on  in  a  Museum  in  Venice   The  need   Temperature  and  Humidity  control  inside  the  various  rooms  with  1ght  Temperature   and  Humidity  set  point  range  (24°C  Temperature  –  50%  rH  with  ±  5%  tolerance).     The  installed  system   It   was   chosen   a   Direct   Expansion   Units   (Mul1func1on   air/water   cooled   units   for   climate   control   +   Fan   Coils)   with   its   regula1on   system   for   temperature   control,   temperature  and  Humidity  values  recording  and  remote  management  via  Internet   access.   Due   to   historical   architecture   of   the   building,   it   was   not   allowed   the   installa1on  of  water  piping  for  hydronic  systems.   Technical  Solu7on:  Air/Water  Units  –  Fan  Coils  –  Ultrasonic  Humidifiers   AG150A fan-coil Bus M-Net fan-coil gatew ay Ethernet (cross cable) fan-coil BUS SUPERVISION BUSpLAN BUS GATEWAY BUS HUMIDIFIERS RS485 bus GATEWAY RS485 bus pLAN RS485 bus HUMIDIFIERS RS485 bus SUPERVISION Results   •  Reduced  energy  requirements:  60W  per  litre   of  spray  per  hour,  corresponding  to  about  7%   of  the  energy  consump1on  of  a  tradi1onal   humidifier.   •  Use  of  demineralized  water  eliminates  the   problem  of  bacteria  improving  the  air  quality.   •  The   adiaba7c   humidifica7on   process   decreases   the   temperature   of   the   air   in   summer7me,   thus   reducing   the   ac7vity   of   the  compressors  and  saving  energy.   •  Extremely  fine  droplet  spray:  the  water  is   finely  sprayed  into  extremely  small  droplets   (few  microns)  easily  and  quickly  absorbed  by   the  air.    

31. EinB2016  –  5th  Interna1onal  Conference  “ENERGY  in  BUILDINGS  2016”     Luigi  Nalini,  Speaker  

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