SOLAR REFRIGERATION SYSTEM +

Basic concept vapour absorption refrigeration system Utilisation of solar energy for cooling purpose In this system ,solar energy is coupled with vapour absorption refrigeration system

Vapour absorption refrigeration system The main parts of basic VARS are: Absorber Pump Generator Condenser Throttling valve Evaporator

R22 - dimethyl ether tetraethylene glycol (DMETEG) R21 - DMETEG VARS PAIRS Ammonia Water Water LiBr R22 - dimethyl ether tetraethylene glycol (DMETEG) R21 - DMETEG R22 - dimethyl formamide (DMF) R12 - dimethyl acetamide R22 - dimethyl acetamide R21 - dimethyl ester

LAYOUT

working Ammonia vapour produced in the generator at high pressure from strong solution of NH3 by an external heating source. The water vapour carried with ammonia is removed in the rectifier and only dehydrated ammonia gets enters into the condenser The cooled NH3 solution is passed through throttle valve and the pressure and temperature of refrigerant are reduced below the temperature to be maintain in the evaporator.

The low temperature refrigerant enters the evaporator and absorbs the required heat from evaporator and leaves the evaporator as saturated vapour Slightly superheated low pressure NH3 vapour is absorbed by weak solution of NH3 which is sprayed in the absorber

Weak NH3 solution(aqua-ammonia) entering the absorber becomes strong solution after absorbing NH3 vapour and then it is pumped to the generator through heat exchanger The pump increases the pressure of strong solution to generated pressure. The strong NH3 solution coming from the absorber absorbs heat from high temperature weak NH3 solution in heat exchanger

The solution in the generator becomes weak as NH3 vapour comes out of it The weak high temperature ammonia solution from the generator is passed to the heat exchanger from throttle valve The pressure of the liquid is reduced to absorber pressure by the throttle valve

COMBINING VARS WITH SOLAR ENERGY The main power consumption of VARS is generator. So,the power is supplied by solar energy Hence the amount of energy required to run the generator is calculated for the desired conditions.

calculations Calculations are performed for the ammonia water VARS based on Condenser Pressure Evaporator Pressure Generator Temperature Absorber Temperature

Calculations related to heat

Calculations related to radiation

EQIVALENT DAYS FOR MONTHS EQUIVALENT DAYS JANUARY 17 FEBRUARY 16 MARCH APRIL 15 MAY JUNE 11 JULY AUGUST SEPTEMBER OCTOBER NOVEMBER 14 DECEMBER 10

AVERAGE SUNSHINE HOURS FOR MONTHS AVG. SUNSHINE HOURS JANUARY 8.6 FEBRUARY 9.5 MARCH 9.8 APRIL 9.2 MAY 8.4 JUNE 6.5 JULY 4.8 AUGUST 5.3 SEPTEMBER 6.2 OCTOBER NOVEMBER 6.9 DECEMBER 7.6

timeline

rEferences Refrigeration and air conditioning -C.P.Arora Solar Energy-Principles of Thermal Collection and Storage - S.P. Sukhatme www.ashrae.org www.wikipedia.org