Search

Utilizing the integrated organic rankine cycle (ORC) and vapour compression refrigeration (VCRs) cycle powered by low-grade thermal energy, the performance of different hydrocarbons, hydrofluorocarbons (HFCs), and novel hydrofluoroole fins was investigated. In this work Engineering Equation Solver (EES) program was utilised for simulation and the results were validated with available experimental results in literature. For low-grade thermal energy, VCRS normally operates in range of 5 and 40 °C, whereas ORC typically operates between 80 and 40 °C. Two essential criteria used to evaluate the system's performance were the coefficient of performance (COPs) and total mass flow rate for each kilo watt total cooling capacity. For the condenser, evaporator, and boiler, the influence of temperature on effectiveness was investigated. The effect of temperature on system performance was studied for the condenser, evaporator, and boiler. Among all the working fluids tested in this combined system, R600a was proven to be the best. Its flammability, though, should draw enough attention. The assumptions and constraints of the modeling were also examined, and model improvement are proposed. [ABSTRACT FROM AUTHOR]

FGM (Functionally graded materials) are the materials with desired special properties mainly the gradient distribution of composition & its microstructure of different metallic & ceramic mixtures in order to achieve improved nature of mechanical, physical & chemical properties. For example, In spaceflight body, outer-surface will be ceramic rich (higher ceramic concentration), because it need to resist 2000k temperature & inner surface will be metallic rich (higher metallic material concentration), because the temperature drop across its body will develop unbalanced thermal stresses. This journal proposes a cost-effective approach for manufacturing FGM (Functionally graded materials) through vibrational coordinator arms & 3D controlled electromagnetic variation across the powder. Then they are used to fabricate the 3D MODEL through SLS (selective laser sintering) layer by layer to achieve the desired gradient properties of the model (ceramic rich outer wall to metallic rich inner wall in space flight body to resist thermal stresses) by additive manufacturing. Metallic & ceramic powders of varying ferromagnetic, mechanical & microstructural properties are selected on requirements of these FGM models & hence have wide range of applications such as spaceflight body and its shields, rocket engines and its components, armour plates, bullet proof vests, implantable bio-medical equipment etc. [ABSTRACT FROM AUTHOR]