Solar Energy Lab Report

Introduction

Solar energy is the widely used source of energy as it is a non-conventional source of energy; we can easily use solar energy for cooking food, charging batteries produce the refrigeration effect etc. Here solar energy is used for getting refrigeration effect. Temperature is decreased using solar energy and this drop in temperature is used for making ice and if the temperature drop is less this can be used for food preservation etc.Vapour absorption system refrigeration system belongs to category of vapour cycle similar to vapour compression system. In vapour absorption system use a liquid medium for absorption of refrigerant and it also known as a wet absorption system.Vapour absorption system widely used in commercial, industrial

Vessel A is filled with pure water, while vessel B is filled with a solution containing on mass basis 50 percent of water and 50 percent lithium bromide (LiBr salt). Initially the valve connecting these two vessels is closed, and both vessels are at thermal equilibrium with the surroundings, which is at 30oC. At 30oC, the saturation pressure of water is 4.24 kPa, and the equilibrium vapour pressure of water-lithium bromide solution (50 : 50 by mass) at 30oC is 1.22

Thus the absorber consists of the weak solution of the refrigerant (ammonia in this case) and absorbent (water in this case). When ammonia from the evaporator enters the absorber, it is absorbed by the absorbent due to which the pressure inside the absorber reduces further leading to more flow of the refrigerant from the evaporator to the absorber and solution becomes strong. This strong solution is pumped to generator using circulating pump. At high temperature water absorbs lesser ammonia, hence it is cooled by the external coolant to increase it ammonia absorption capacity.The refrigerant leaving the evaporator enter the absorber, where it is absorbed by the absorbent. The refrigerant then enters the condenser while the remaining weak solution enters back to the absorber and the cycle is repeated. When the refrigerant enters the absorber from evaporator its volume gets decreased so compression process is done by the absorber in the VAR