Seminar On“Hybrid Desiccant Cooling System”

Presented by Guided By Kirankumar Gosavi Prof. P.D Shelke (132031)

INTODUCTION

• HDC System is new Technology use to Regulate Humidity from

conditioned space using Desiccant Wheel

• The Desiccant wheel is Heart of the system .

• The Use of Solar Thermal energy for Regeneration of desiccant

• The system use two energy sources solar & Electricity

hence it is Hybrid system.

HUMAN COMFORT

The above Four Atmospheric Condition affect Human Comfort.

Most of People (90%) are most comfort when Air Temperature Is Between 18 ‘ c- 22’c and RH 40-50%

the system using Desiccant wheel to control humidity ,Indirect evaporative Cooler

for cooling.

HDC System is work in conjuction with Conventional vapour Compression System for Humidification ,hence to reduce Latent load

Temperature Humidity Air Purity

Air Movement

Conventional cooling system for dehumidification

Limitations High power required to reduce the latent load Frost in evaporatorCFC emission

1. a grille2. An electric fan3. freezing cold pipes 4. a heating element5. another grille.6. A plastic float7. electric switch

Desiccant Dehumidification

The use of chemical (or physical) absorption of water vapour to dehumidify air and reduce the latent cooling load in AC System

Two types of desiccant systems

Liquid (sorbent)

Dry.

DESICCANT WHEEL

A desiccant dehumidifier is a tool for controlling humidity (moisture) level for conditioned air spaces.

HOW DESICCANT ABSORB MOISTURE ?

Desiccants remove moisture in one of three ways; absorption, adsorption or through a chemical reaction or change.

SYSTEM DESCRIPTION

It consists of Desiccant wheel, rotary heat recovery wheel, heater, supply fans and cooling coil The Desiccant wheel divided into two sections: dehumidification and regeneration.

PSCHOMETRIC CHART

Liquid desiccant cooling system

1.Liquid desiccant System2.Indirect evaporative cooler3.Solar Collector4.Microprocessor Based control unit.

LIQUID DESICCANT DEHUMIDIER

It Consist of two System

Air Drying System Desiccant Regeneration

Hybrid desiccant air conditioning system:

• The Desiccant Wheel is also used in Conventional Vapour Compression Ac System.•Using Partial heat of Condeser and External Gas Source for Desiccant Regeneration.

DESICCANT MATERIALS

“A substance, that has a high affinity for water and is used as a drying agent.”

Two major categories of desiccants are

Adsorbents.

Activated alumina, silica gel, molecular sieves, zeolite etc

Absorbents LiCl,hpx,etc..

Advantages

Reduce moisture at high moisture Rate, much below 40f dew point temperature

High COP can be achieve. No CFC Production,it is clean and eco -friendly. It decreases the electrical demand. Excesses exhaust heat from regenerator can be used to

heating water. Stop the growth Microorganism

LIMITATIONS

Applicable for only Hot humid region. High initial cost A considerable amount of thermal energy is

necessary for the reactivation process and it increases with the dehumidification requirements and with the reactivation temperature.

Major limitations of liquid system are corrosion and desiccant droplet carry over with air stream

APPLICATIONS

Industrial applications Mostly pharmaceutical company’s In some commercial or institutions building Crowded building such schools, restaurant,

hospital, mosque etc, which are located in hot, semi humid regions

In the cities of humid region Commercial applications including refrigerated

warehouse, ice rinks, schools, supermarket and hospital

ENERGY CONSUMPTION AND FEAIBILITY STUDY

Energy consumption and feasibility study in IRAN The work studies of the economic feasibility of integrated a solid wheel desiccant wheel with

conventional vapour compression air conditioning system in IRAN

Air conditioning space of 1500 meter cub. area ,the experimental studies conclude that the annual cost saving for the system is 418.39 USD for gas price of 0.141USD/kg

The payback period of hybrid system is less than 5 years with initial cost of 1700 USD.For Domestic roof top application it was determined that a 30kw capacity LDAC could dehumidify and cool 1000 m cub. Of residential buildings in perision gulf in Iran.100 m.square of flat plate solar collector to dehumidify and cool 1000m.squre area

DEVELOPMENT AND FUTURE SCENARIO

FUTURE SCOPE

REFERANCES

 

[1] ASHARE JOURNAL January 2007 by M.H.Saidi

& S.Vazirifard

[2] Energy and feasibility study ,k.ghaliu,beriut ,Beirut university ,Lebanon

[3] Investigation on solar energy driven liguid desiccant cooling fortropical Climates By Raju Subhra Das,Pretik kumar shaha and sanjeev Jain,IIT delhi

[4] www.youtube.com

[5 ] www.csiro.com

[6] Munter.Dry cool ,heat and mass exchange industry ,in USA

Desiccant wheel broacher.

[7] www.novelaire.org

[8] www.slideshare.com

[9] www.wikipedia.com

[10] United States Patent Patent No.: US 2011/0138832 A1

Jun. 16, 2011