politecnico di torino, DK
Degree & Study program
Master in MSc mechanical engineering
Thesis topic proposal: Solar driven Vapor Absorption Refrigeration system Design
Here is my idea to be competitive on the market on global the refrigeration system, the vapour absorption refrigeration system is more advantages to address the mark on global market that Hot tropical country such as Africa, south American, north America and mid east country, Therefore. The alternative renewable energy sources will become an important means to replace the ordinary conventional refrigeration system or vapour compression refrigerators .Solar radiation is a clean form of energy, so using it to drive the cooling cycles becomes attractive.
The second reason is most of industrial processes use a lot of thermal energy by burning fossil fuel or electric energy to produce steam or heat for their purpose. After the processes, heat is rejected to the surrounding as waste. This waste heat can be converted to useful refrigeration by using a heat operated refrigeration system, such as an absorption refrigeration cycle. This can reduce electricity purchased from utility companies for conventional vapour compression refrigerators.
Off course different type of refrigeration system such as vapour compression refrigeration, absorption refrigeration cycles etc... Let summarize the refrigeration system that listed above shortly.
Vapor compression refrigeration
The working fluid (refrigerant) is compressed isentropically or in a reversible adiabatic to the condenser pressure at the compressor. The refrigerant is then condensed in a heat exchanger giving saturated liquid. Then isentropic expansion takes place in order for bringing the temperature and pressure of the refrigerant to evaporator pressure and temperature. At the evaporator, it evaporates by giving the refrigerating effect of the required item. After evaporation, it enters the compressor again and thus completing the cycle.
Fig1.1VCR system for domestic refrigerator
Vapor absorption refrigeration
An absorption refrigeration process replaces the compressor. Now in vapour absorption refrigeration system, instead of compressing a vapor between the evaporator and the condenser as in a vapour compression refrigeration cycle, the refrigerant is absorbed by a secondary substance, called an absorbent, to form a liquid solution. The liquid solution is then pumped to the higher pressure.
Fig1.3 Vapour absorption refrigeration systems
Description of thesis work
Having side that, the thesis study consists of the design the generator, condenser, absorber, evaporator and flat plat solar collector and some other selected parts like pumps and thermostat expansion valves. The rating and sizing of heat exchangers are two important problems encountered in the thermal analysis of heat exchanger. The rating problem concerned with the determination of the heat transfer rate and the fluid out let temperature for prescribed flow rates, inlet temperatures, and allowable pressure drop for existing heat exchangers, hence the heat transfer surface area and the flow passage dimensions are available. On the other hand sizing involves determination of the dimensions of the heat exchanger, which is selecting the appropriate heat exchanger type and determining the size to meet the requirements of specified hot and cold-fluid inlet and out let temperatures, flow rates and pressure drops.
The objective of this project is to design a solar driven vapour absorption refrigerator to be used in hot area which after few developments is going to be a multipurpose refrigerator i.e. to be used for air conditioning, preserving foods, preserving vaccines (medicines) . The machine is assumed cost effective, robust or healthy so that it is going to be accessible for everyone in need.
The specific objective of this project is to design an absorption refrigerator which is driven by solar energy.
Design of condenser & generator.
Design of evaporator & absorber.
Design of solution heat exchanger.
Design of flat plate solar collector and some selected parts.
Part drawing and assembly
This project has so many advantages.
• The system has no negative impact on the environment (environmental friendly) as well as reduces the energy price.
• The company want to address the market on the hot area I believed it will be a good guidance and good reference for further research work to apply for the market.
• In addition, it will be a basic reference for vapour absorption system for the industrial application vapour absorption chillers.
Fig.1 The proto type of assembly of vapour absorption refrigeration
A schedule of work is given below that outlines the various tasks that need to be completed in order to finish the thesis project outlined in the proposal above. This is only a tentative schedule that is meant to be flexible and adapt to unforeseen delays or unexpected lengths of various tasks.
Figure 2: work schedule