Control Volume Energy Based Model for a Thermal Lag Engine

The Thermal Lag Engine (TLE) was patented by Peter Tailer in 1995 proposing an ultimately simple engine with a single moving part, the piston. During the return of the piston the engine gas temperature and pressure increase, because of the energy input from two processes: heat transfer from the hot source and compression work from the engine’s return mechanism. These processes happen at different speeds; energy gain from heat transfer happens slower than that from compression work. The TLE uses this time difference to diphase the engine’s heat gain from the compression work, which is the displacers function in conventional Stirling engines. Further the piston’s motion exposes and hides the cold heat exchanger creating the intermittency needed between cooling and heating for the engine to work. Even though this engine follows a Stirling like cycle, due to the time dependency of the engines return mechanism, the geometric dependence of the engine cooling mechanism, and the fact that these are also coupled, makes the modeling of this engine complex and only possible through a dynamical modeling approach. A previous attempt to model this engine has been done by Prof. Frank Wicks and Carlos Caminero from Union Collage, NY, and the results of this model were presented. This paper proposes a control volume energy based approach to modeling this engine, states a model and the results of its simulations. Further it presents a physical explanation of the TLE workings and states are of improvement. It concludes that the TLE could be a competitive engine in the future.