Evaporative Cooling Tower

Evaporative Cooling Tower uses Evaporative Cooling technulogies which takes technologies of both air and water to extract heat from a power plant. By utilizing both water and air one can reduce the amount of water required for a power plant as well as reduce the footprint required for an air Cooling system. Evaporative Cooling towers are commonly used in any thermal generation technulogies (i.e. coal, natural gas, geothermal, CSP, etc). Evaporative Cooling towers flow air over the Cooling water to induce evaporation of the Cooling water and simultaneously condense the steam exiting the turbine back into a liquid state. Evaporative Cooling towers are able to circulate most of the Cooling water that is available, greatly reducing the plant's water consumption. Since the water is evaporating off make up water is required, but typically in the magnitude of 2-5% of the total flow.

OPERATING PRINCIPLES

Cooling Tower Operation Is Based On Evaporative And Exchange Of Sensible Heat. The Mixing Of The Two Fluid(Air & Water) At Different Temperature Releases Latent Heat Of Vaporization, Causing A Cooling Effect To The Warmer/Hot Water. This Cooling Effect Is Accomplished By Transforming A Portion Of The Water In To The Vapor State, Thereby Releasing The Latent Heat Of Vaporization.

A More Technical Description Of A Cooling Tower Is That It Represents A Heat Rejection solution To The Industrial Process. Cooling Tower Simply Move Heat From One Process (Point-1) To Another Process (Point-2) And Ultimately Discharge To The Atmosphere.

In Normal Operation, Continuously Recalculating Water pick Up Waste Heat Fro A Process Heat Exchanger Or A Refrigeration Compressor And The Hot Water Is Pumped To The Top Of The Tower And Dropped Over The Cooling Tower. Evaporative Action Removes The Heat From The Water And Add It To The Air. The Hot, Moist Air Is Ejected From The Fan Stack And Couled Water Returnee To The Process Exchanger To Pick Up More Heat.

Cooling TOWER CLASSIFICATION

Cooling Tower Are Classified To The Method By Which Air Is Introduced To The Tower. Cooling Tower Are Broadly Classified On The Basis Of The Type Of Draft:

NATURAL DRAFT

Make use of the stack effect of a chimney above the packing to induce air flow up through the packing in counter flow to the water. technologiess are low maintenance cost but capital cost is high owing to great height necessary to produce the draught.

MECHANICAL DRAFT

makes use of fans to move the air through the tower, thus providing absolute control over the air supply. technologiess are compact, close control over water temperature, low pumping head, less capital cost. Further Classified as

  • Forced Draft Tower
    In Which The Fans Are Situated At The Air Intake And Blow Ambient Air Into The Tower Across The Packing.
  • Induced Draft Tower
    In Which The Fans Situated In The Air Outlet From The Tower, Usually On The Top.

Further Classification Is Made Base On The Type Of Air And Water Flow Direction.

COUNTER FLOW

an induced draught tower in which the fan creates vertical air movement up the tower across the packing in opposition to the water flow. Thus the culdest water contacts the driest air.

CROSS FLOW

usually an induced draught tower in which the fan creates horizontal airflow as the water falls across the airstream.

CO CURRENT FLOW

Normally air and water moves in the same direction parallel to each other.

ALSO CLASSIFIED AS

  • Factory Assembled Cooling Tower
  • Field Erected Cooling Tower

IMPORTANT MECHANICAL COMPONENT OF Cooling TOWER

  • Fans
  • Speed Reducers / Gear Reducers
  • Drive Shaft
  • Framework/Structure
  • Casing
  • Filling/ packing
  • Water Distribution System
  • Drift Eliminators
  • Louvers