| Popis: |
The techniques used in old buildings, as in suspension bridges, improved in the course of time, generating curved structures that minimize materials and maximize strength. Among the curves used there is the catenary curve, which is an excellent way of building with arches that are supported by the weight and provide stability, flexibility and strength to the structures. The curves catenaries offer better distribution of forces and tensions and its main advantage is that the forces applied in any curve point are divided equally by all her. As a result, structures built in this way have the maximum strength with the least possible use of material. In this work we studied an alternative use in hermetic compressors used in domestic refrigeration, with the objective of reducing material and better thermal efficiency and structural. The catenary curves are applied to the geometry of the cylinder block, keeping the other parts, piston, shaft and connecting rods in their original format. A preliminary study allowed the selection of a viable set of values for the two parameters that determine each catenary. A compressor model was created in the software Claim Space and several simulations were performed in Ansys software for catenary different selected. As criteria for the selection of alternatives sought to maximize the area of heat transfer and minimize the structural tensions. Another important criterion is the minimum thickness of the cylinder to prevent the gas permeability of gray cast iron. Computer simulations showed that the catenary curves produce an efficient temperature distribution, caused by the significant increase in the area. As a result, we obtained an excellent improvement in the rate of heat transfer, so as to minimize the gas temperature at the compressor outlet. Thus the fluid arrives at the condenser with a lower temperature, improving the efficiency of the cooling system. In evaluating the stress simulations showed small variations in the structures, showing the applicability of the catenary in thermomechanical equipment. In addition, there was a noticeable reduction in volume and mass in the compressor cylinder block, to ensure the sustainable use of raw materials. The changes suggested in this work may represent savings in the industry compressors that can be reversed to consumers of household coolers and also industrial. |
