Prior to charging, care was taken to make sure all parts are clean. whereby, regenerator plastic block and its parent Perspex tubes are cleaning to prevent any molecules of undesirable materials, dirty and grease that may subsequently appear as unwanted or that chemically react or absorbed by the Gd metal surface, or with working fluid forming undesirable corrosion products.
Subsequently, the cleaning procedure was carried out by washing with a detergent and water, drying in a free stream of air by a blower. Next, the cylindrical enclosure was flushed with a small amount of working fluid and then re-evacuated, repeated this several times, when evacuation process was completed, …show more content…
Whereby, the hot reservoir of the prototype temperature that is generally within 1K of the ambient temperature. Therefore, in each experiment, the ambient temperature was set slightly above the material’s transition temperature to ensure that the system operated near its optimal temperature range.
However, like any refrigerator, an AMR operating at periodic steady-state produces a net flow of heat from a cold source to a hot sink. Since, a unique feature of an AMR cycle is that at every section of the bed the refrigerant is undergoing its own unique local cycle. Although, the net heat transfer cycle occurs between reservoirs at TC and TH, the bulk of the working material does not have to interact with these reservoirs directly. This is conceptually similar to a cascade system of a large number of magnetic refrigerators .
On the other hand, the experimental AMR executes the conventional four steps of the AMR cycle: Magnetization, Hot blow, Demagnetization and Cold blow. Time spent for each step as well as the total cycle time is controlled by varying the acceleration and velocity of the Pneumatic …show more content…
Fig. (4.16): Application of the magnetic field distribution during the refrigeration cycle and the movement of the pistons in inside the regenerator AMR. 
Thus, at any power level setting, the AMR was allowed to reach steady state conditions. Traditionally, steady state conditions are defined as the state when temperature at each thermocouple locations approximately does not change with time. However, and due to the limitation of the laboratory, and after several experiments found the initial control of the fluid flow rate was a difficult process, also the measuring of the actual time variation of the fluid flow rate. Furthermore, due to the little mass of fluid flow, the experiments didn’t reach the desired range with the suitable temperature span.
On the other hand, cooling effect was very small and because of, experimentally the regenerator dose not separated from the flow guide plates by a gap to ensure that all heat transfer between the regenerator and the surroundings occurs through the flow channel. The heat conduction through the assembly should be low because of the low conductivity of both the Perspex and the Plastic flow