Emissions Control Systems Flashcards
7 cards from real LEC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Emissions Control Systems flashcards as text
Under the EPA's anti-tampering provisions in 40 CFR Part 1033, which action by a locomotive operator is prohibited?
Answer: Removing or disabling emissions control equipment
Federal anti-tampering rules prohibit removing, disabling, or bypassing any emissions control device on a locomotive, which can result in significant civil penalties.
Which idling reduction technology automatically shuts down a locomotive engine after a set idle period to reduce unnecessary emissions?
Answer: Automatic engine stop-start (AESS)
Automatic engine stop-start systems shut down the prime mover after a programmed idle period, reducing fuel consumption and emissions during extended stops.
How does altitude affect diesel engine emissions on a locomotive?
Answer: Higher altitude increases PM and CO emissions due to reduced air density
At higher altitudes, reduced air density lowers the oxygen available for combustion, leading to richer mixtures and increased particulate matter and CO emissions.
What is the consequence of operating a locomotive with a malfunctioning DEF doser in an SCR-equipped engine?
Answer: NOx emissions will exceed EPA limits
A malfunctioning DEF doser stops urea injection into the SCR catalyst, eliminating NOx reduction and causing NOx emissions to far exceed regulatory standards.
Which of the following best describes the difference between active and passive DPF regeneration in locomotives?
Answer: Passive uses natural exhaust heat; active requires additional fuel or heat injection to burn soot
Passive DPF regeneration occurs naturally when exhaust temperatures are high enough to oxidize soot; active regeneration requires additional heat input when temperatures are insufficient.
A locomotive engineer reports that the exhaust stack is emitting white smoke during cold startup. What is the most likely cause?
Answer: Water vapor and unburned fuel condensing in cold exhaust
White smoke during cold startup is typically water vapor condensing and unburned fuel misting as the engine and exhaust system reach operating temperature.
Under EPA's locomotive remanufacture standards, when a Tier 0 locomotive engine undergoes a major overhaul, what emissions requirement applies?
Answer: It must meet the same tier standards as when it was new
Under 40 CFR Part 1033, remanufactured locomotive engines must meet the emissions standards that applied when the engine was originally certified, maintaining the original tier level.