Theoretical model of a α-type four-cylinder double-acting stirling engine based on energy method

The double-acting Stirling engine is a type of Stirling engine which comprises four engine units with only four pistons. In this paper, an energy method is proposed for solving the relationship between the crank angle of the main shaft and the work generated by the working fluid. The proposed method is capable of finding the relationship more efficiently without solving the equations of motion of all the links of the linking mechanism. The wobble yoke mechanism is chosen as the transmission mechanism of the proposed engine. A modified non-ideal adiabatic model was employed for predicting the transient variation in the thermal properties of working fluid. The transient behavior of the kinetic energy and potential energy of the linking mechanism, the work loss due to friction, shaft work, and indicated work were discussed. The simulation results show that the maximum shaft power of the proposed engine is 1103 W at 878 rpm under the loading torque of 12 N m at the heating temperature of 1200 K. In addition, the regenerator's porosity of 0.666 gives the maximum shaft power 683 W for the proposed engine. The proposed model has successfully predicted the performance of the four-cylinder double-acting Stirling engine. •A new method for analyzing a double-acting Stirling engine is proposed.•The transient behaviors and performance of the proposed engine are simulated.•Effects of loading and charged pressure on the performance are studied.•The maximum power produced by the proposed engine is 1103 W at 878 rpm.