16 September 2018

Advantages and disadvantages of Stirling engine

A Stirling engine is operated by cyclic compression and expansion of air or other gas at different temperatures and convert heat energy into mechanical work thus it is also called a heat engine. Let us have a deep insight into the advantages and disadvantages of the Stirling engine to know more about it. 

Advantages of Stirling engine :

  • Stirling engines can run directly on any available heat source not produced by combustion so they can run heat from biological, geothermal, nuclear sources or solar.
  • Most Stirling engine types have the cool side of the engine bearing and seals. They only need less lubricant and last longer than other types of engines that reciprocate.
  • In some ways, the engine mechanisms are simpler than other types of engines that reciprocate.
  • No valve is needed. 
  • A Stirling engine uses a single-phase working fluid that keeps an internal pressure close to the pressure of design.
  • Low operating pressure permits the use of lightweight cylinders in some cases.
  • They can be constructed to run smoothly and without an air supply.
  • In cold weather, they start easily and run more efficiently.
  • They can extremely flexible.
  • They can be used as CHP in winter and as a cooler in summer.
  • Waste heat is easily harvested.
  • Stirling engine is useful for duel-output heat and power systems.

Disadvantages of Stirling engine :

  • Stirling engine requires heat exchangers for heat input and for heat output.
  • For efficient operation, all thermodynamic cycles require large temperature differences.
  • Dissipation of waste heat is especially complicated because coolant temperature is kept as low as possible to maximize thermal efficiency.
  • A Stirling engine cannot start instantly and literally needs to warm up. It is true for all external combustion engines but for this warm-up time may be longer.