Question

Use your own words to answer the following questions. Please no handwriting.

Determine what conditions should be considered when implementing passive vs. active cooling techniques.

Describe the advantages of absorption cooling that occurs in a solar cooling system.

Describe two equipment requirements and limitations that must be considered in the analysis and design of solar powered absorption systems.

What are the disadvantages of desiccant solar cooling systems?

Answer 1

Active cooling means that you have heat sink as well as a fan and passive cooling means that you just have heat sink and you do not have a fan. According to performance active cooling is best because it has fan to dissipate the heat very quickly from the heat sink but in some applications passive cooling would be better because it would be quiter therfore the condition should be consider. if you are living in hot environment, definetely go for active cooling and if you want to build very quite computer system then go with passive cooling.

Absorption cooling (chiller operate with less noise and vibration than compressor base chillers. The more absoption cooling cyscle are used, the efficient they are. For years , absorption cooling have been used to make ice before electric light bulb were invented this ice can be stored and used as ice battery for cooling when the sun is not shining.

Two required equipment in solar cooling system is evaporator and condenser.

The Evaporator condenser and expansion valve connected with the pipe and vapor generator with absorver. there is in the absorver are ammonia and water and this is connected with the evaporator and analyzer in the vapor genarator and a rectifier are there in the way of vapor generator and condenser.

working -: solar energy is given to the generator and pump start working. In the generator vapor are formed ammonia and in some water formed then from the analyzer the water vapor come to the absorver the this vapor will go to the condenser but in the way between analyzer and condenser is a rectifier,. Rectifier is heat exchanger and this will change the water vapor changed into liquid formed and go to generator and this water go to the absorver. and pure ammonia vapor will go to the condenser and ammonia will changed into liquid form and this liquid pass through expansion volve. There will be reduce in pressor and go to evaporator with low pressor and will go to the absorver and in the evaporator the space will be cooled which is we wanted.

Disadvantages

1. Liquid desiccants like water ammonia and other salts are corrosive and can damage the desiccant system.

2. Any carry-over of liquid desiccant along with supply air stream can cause harm to the health of the occupants.

3. Desiccants of aqueous salts also face the problem of crystallization.