Thesis Statements About Abortions

solar cooling by absorption machines

The ecological alternative when control a building is the use of sources renewable energy or recycling of surplus energy from other processes.

For these applications are used absorption machines. These machines differ from air conditioning machines of conventional vapor compression in the external source of energy for its operation is thermally and non-electrical.

In particular an excellent source of energy is solar power, many facilities are used only for generating hot water, showing large surpluses in many cases directly dissipated to the environment, especially in summer months the demand cooling is higher.

Among the various types of stress absorption machine: Machines

• simple fact ammonia / water.
• double effect machines water / bromide Litres.

SIMPLE MACHINES EFFECT

explain

first mode of operation of single-acting machines from each of the constituent elements and shown in the following scheme:

• 
  
  Builder: containing a solution of ammonia dissolved in water at high pressure (about 20 bar). The effect of external thermal energy fed into the dissolved ammonia is vaporized, separated from the water. The steam generated is directed into the condenser. Capacitor
• : this exchanger ammonia condenses releasing heat to another fluid, which may be water or air.
• expansion valve: ammonia liquid at high pressure expands sharply lowering its pressure, so that goes to state two-phase (liquid + vapor).
• Evaporator: ammonia evaporates absorbing energy utilization circuit, generally water that feeds a set of fan coil air conditioned in charge of the different rooms.
• Absorber: low pressure steam to dissolve it goes back into the water from the generator.
• Pump: is responsible for circulating the mixture of ammonia dissolved in water to the generator.

These machines have a COP between 0.6 and 0.8.

These machines require a thermal fluid to a temperatra between 70-90 º C. In case of using solar energy are suitable vacuum sensors.

DOUBLE EFFECT MACHINES

As for dual-purpose machines operation is similar except that the fluid refrigentante in this case is water and the absorbent is a salt (lithium bromide).

presents the same elements as a single engine generator effect by adding a low temperature.

generation refrigerant fluid (water) and regeneration of the absorbent is carried out in 2 different stages, hence the name of double effect.

The following diagram illustrates how it works:

concentrated LiBr solution is sucked from the absorber and transported to the low temperature generator. Once there is boiling because the heat transferred by the refrigerant (water vapor) produced by the generator high temperature, releasing water vapor and produce a solution even more concentrated LiBr, part of which is sucked by a pump and transported to the high temperature generator and the other part returns to the absorber before a recovery from low temperature where it is cooled.

In the high temperature generator is boiling concentrated solution by the effect of external heat source, generating refrigerant at high temperature. As mentioned above this high temperature steam loses heat in the low temperature generator, producing a partial condensation thereof. Therefore, the low temperature generator also acts as a capacitor.

The steam generated in the low temperature generator flows into the condenser where the latent heat yields the cooling water circuit changing state (vapor to liquid).

refrigerant produced in the two generators, and in liquid is sprayed through a spray on a heat exchanger tube, inside of which circulates water is cooled in this process. The water spray is evaporated in this heat exchange, passing back to the absorber where it meets part of the saturated solution from the generators to be absorbed by it.

This rather complex process able to increase the COP of the machine up to 1 - 1.2.

These machines require a temperatra thermal fluid above 150 ° C. In case of using solar energy requires the use of steerable parabolic collectors .
This technology offers an excellent opportunity for an environmental conditioning advantage of the best solar energy so accessible that we have in the Mediterranean countries.