Contributions to the Stirling Engine Study

Abstract

In the process of transforming thermal energy into mechanical work, among the known thermal machines, the Stirling engine is the one that can achieve the highest yield (theoretically up to the maximum yield of the Carnot cycle), although in practice it is reduced by the properties of gas and materials used such as friction coefficient, thermal conductivity, melting point, breaking strength, plastic deformation, etc. This type of engine can operate on the basis of a heat source irrespective of its quality, whether it is solar, chemical, nuclear, biological, etc. Unlike internal combustion engines, the Stirling engines can be economical, quieter, safer and less maintenance-free. They are preferred in specific applications where these advantages are reaped, especially if the main objective is not to minimize investment costs per unit of power (RON/kW) but to those per unit of energy (RON/kWh). Compared to internal combustion engines of a given power, the Stirling engines require higher capital expenditure, are larger and heavier, for which reason, viewed from this point of view, this technology is uncompetitive. For some applications, however, a sound analysis of the earnings-to-revenue ratio may favor Stirling engines versus internal combustion engines. More recently, Stirling's benefits have become visible compared to rising energy costs, lack of energy resources and environmental issues such as climate change. Increasing interest in Stirling engine technology has spurred research and development in this area lately. Uses a range of water pumping to astronautics and power generation based on rich sources of energy incompatible with internal combustion engines such as solar energy, or plant and animal scraps. In this respect, the four-stroke four-stroke engine type Stirling is the most advantageous, being driven continuously from the piston. For this reason, it has a stranger load feature, which is said to be inappropriate for car use (the more crankshaft driven crankshaft, although having less mechanical efficiency, have a much longer stable and respond quickly to changes in the working regimes required by a vehicle, especially due to the large inertial help of the shaft, plus the steering wheel, which are more "nerve-wise" and therefore more dynamic). This can, however, be easily corrected in Stirling engines by using multiple cylinders simultaneously, trapped on the same shaft (multi-cylinder Stirling), the shaft having a high inertia, which can be further enhanced by -a wheel. Even though the cylinders work most of the time in motor regimes, they are permanently connected to the output shaft which must have a very high inertia in construction, the movement at the output of the motor being picked from the shaft.