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.