Using sign Convention indicate which quantities are positive

Using sign Convention, indicate which quantities are positive and which are negative (e.g. is W + ve or W -ve) is stirling engine the one that have two displacer (small and large)

Solution

Stirling cycle consists of four thermodynamic processes:

Considering the sign convention: Q is positive if heat is added to the system, and negative if heat is removed; W is positive if work is done by the system, and negative if work is done on the system.