Improving the Quality of Elements of Flat Heat Exchangers and Roof Coatings Received by the Elastic Working Tool

Abstract

Abstract The article discusses the issues of improving the quality of elements of flat heat exchangers and roof coverings. This is achieved by increasing the strength of the sheet metal, heat exchanger elements and by increasing the thickness of the roof covering. It is advisable to make such elements using an elastic working tool. The use of elastic media as a working tool makes it possible to significantly reduce the cost of die tooling, but it has drawbacks. The main one is small pressures in an elastic medium that is not enclosed in a closed volume; therefore, the forces that arise are not enough to deform alloys with a thickness of more than 0.5 mm. It is possible to increase the pressure and, accordingly, expand the technological capabilities by reinforcing polyurethane with high-strength aramid fabrics. The paper considers the behavior of a cylindrical polyurethane specimen during its settlement. The theoretical model coincides with the experiments. Two types of specimens were upset, cylindrical with reinforcement with different types of aramid fabric. The experiments carried out show that the reinforcement leads to a significant increase in the rigidity of the working elastic working tool and, as a result, to the expansion of technological capabilities and the range of products obtained by local processing with an elastic medium. This leads to an increase in the performance of flat heat exchangers, as well as an increase in the quality and strength of the roofs.