Mathematical modeling and testing of a reversed stirling cycle water dispenser

Abstract EN

One of the most attention-grabbing concerns nowadays is the global warming and environmental impact of different machines.

Also, the depletion of the fossil fuel is another important issue which increases the philosophy of developing low power consuming machines.

The traditional refrigeration machines, vapor compression machines, have two disadvantages namely: the use of environmental harmful refrigerants and the large amount of input power needed to produce the desired cold.

The Stirling cycle is thought to be an alternative for the previously mentioned machines; since it have the ability to be reversed.

As the Stirling cycle is reversed, it could be used as refrigerator and heat pumping machine.

Several advantages are achieved from using the reversed Stirling cycle including; compact lightweight machines, environment friendly working fluids, quiet machines, fast cool-down technology and the lowest required input power; since the Stirling machines have the highest possible efficiency of the Carnot cycle.

A reversed Stirling machine is adopted to be used as a water dispenser for supplying fresh cold/hot water.

A schematic diagram for the reversed Stirling dispenser machine was prepared and a mathematical model was set.

The different geometrical and operational conditions were optimized to achieve the desired water temperatures at lowest possible input power and obtain acceptable cooling/ heating capacities at reasonable COP.

The different machine parts was then manufactured according to the theoretical results and assembled together.

The machine was coupled to an electrical motor and tested at different operational conditions.

The performance of the machine was evaluated based on the theoretical results.

A reasonable cooling/ heating capacities were obtained and subzero temperatures were achieved at no load conditions.