In this article, we are going to explain what is turbocharger. I have also covered its parts working, diagram, pros, cons, and application. A PDF is provided at the end.
What is turbocharger
A turbocharger, or turbo, elevates an internal combustion engine’s efficiency and power by compelling extra air into the combustion chamber. The compressor, a vital turbocharger component, draws in and compresses ambient air before introducing it to the intake manifold under higher pressure.
Unlike naturally aspirated engines, the turbocharger enhances efficiency by increasing the density of intake gas, leading to a greater air mass during each intake stroke and boosting engine power. The turbocharger’s compressor is powered by the kinetic energy of exhaust gases. Additionally, it enhances fuel efficiency by recovering waste energy from the exhaust, promoting thorough fuel combustion.
Parts of turbocharger
Blow-Off (Bypass) Valves
Blow-off valves (BOV) on the intake tract prevent turbo compressor surge. Installed between the compressor discharge and throttle body, BOVs vent excess boost to the atmosphere during rapid throttle closure, eliminating surge.
Wastegates
Wastegates control engine boosts pressure on the exhaust side. Internal Wastegates regulate flow within the turbine housing, while external Wastegates added to exhaust plumbing improve turbine performance by reintroducing bypassed flow.
Oil & Water Plumbing
For Garrett ball-bearing turbochargers, proper oil and water plumbing are crucial. An oil inlet restrictor is recommended for high oil pressure, and water-cooled center housings use engine coolant to prevent oil coking during heat soak-back.
Selecting the Right Turbocharger
Choosing the appropriate turbocharger involves considering factors like target horsepower, airflow requirements, and application type. Smaller turbochargers suit applications requiring rapid boost response, while larger ones are preferable for track-oriented cars prioritizing peak horsepower.
Journal Bearings vs. Ball Bearings
Ball-bearing turbochargers, specifically the Garrett Cartridge Ball Bearing, offer significant performance improvements. They provide exceptionally crisp throttle response, faster spool-up, lower power consumption, reduced oil flow requirements, and improved rotor dynamics for enhanced reliability and durability.
Working of turbocharger
A turbocharger operates as an air pump that takes in air at ambient pressures, compresses it to higher pressures, and directs the compressed air into the engine through the inlet valves. Historically more prevalent in diesel engines for enhanced performance, turbochargers are now increasingly utilized in the production of petrol engines to meet stringent emissions control standards.
To increase engine power, a balance between air and fuel is crucial. Augmenting these elements within specified limits boosts power, but excessive fuel can lead to a rich mixture with associated issues, while an overabundance of air, known as running too lean, can be destructive.
Meeting power requirements involves increasing airflow, a task where air, naturally under pressure, is forced into the cylinders during the engine’s induction stroke. Turbochargers, functioning as air pumps, further increase airflow by compressing air and delivering it into the engine. This compressed air, when mixed with injected fuel, enhances combustion efficiency, thereby elevating engine power output.
In situations where engines operate regularly at high altitudes with lower air density, turbocharging becomes valuable, restoring lost power caused by decreased air pressure at such elevations.
Capture, Spin, Vent, and Compress:
- Capture: Instead of escaping through the exhaust pipe, hot gases from combustion flow to the turbocharger. In a twin-scroll turbocharger, exhaust from pairs of cylinders in alternating sequences reduces interference, maintaining a stronger exhaust flow.
- Spin: The exhaust strikes the turbine blades, spinning them at high speeds of up to 150,000 rpm, eliminating turbo lag through the alternating pulses of exhaust.
- Vent: Exhaust gases, having served their purpose, flow through an outlet to the catalytic converter for pollutant scrubbing before exiting through the tailpipe.
- Compress: Simultaneously, the turbine powers an air compressor that gathers and compresses cold, clean air to 30% above atmospheric pressure. This oxygen-rich air flows to the combustion chamber, enabling more complete gasoline burning and generating 30% more power than a non-turbocharged engine of the same size.
Pros of Turbochargers
- Increased Power Output: Turbochargers significantly boost engine power.
- Improved Fuel Efficiency: Enhances combustion efficiency, contributing to better fuel economy.
- Reduced Displacement: Achieves high power with smaller engine sizes.
- Altitude Compensation: Maintains engine performance at high altitudes.
- Emissions Control: Optimizes combustion for environmental compliance.
Cons of Turbochargers
- Turbo Lag: Delay in power delivery, especially at lower RPMs.
- Increased Complexity: Introduces additional components and maintenance challenges.
- Heat Generation: Generates heat, impacting engine compartment temperatures.
- Potential Engine Stress: Higher pressures may stress engine components.
- Oil and Cooling Requirements: Requires proper lubrication and cooling for optimal performance.
Applications of Turbochargers
- Automotive Engines: Turbochargers enhance performance and fuel efficiency in cars, trucks, and motorcycles.
- Aircraft Engines: Essential for maintaining optimal performance at varying altitudes in aviation.
- Marine Engines: Used in ships and boats to increase power and efficiency.
- Power Generation: Improves efficiency in gas and diesel generators in power plants.
- Construction and Mining Equipment: Integrated into heavy machinery for increased power in demanding conditions.
- Industrial Engines: Common in large industrial engines to enhance power and efficiency.
- Locomotives: Employed in locomotives to improve the performance of diesel engines.
- Agricultural Machinery: Turbochargers optimize engine power and efficiency in tractors and agricultural equipment.
- Military Vehicles: Utilized for improved engine performance and responsiveness in military vehicles.
- Power Sports: Found in high-performance motorcycles, ATVs, and snowmobiles to enhance speed and power.
