Today’s emphasis on improving fuel efficiency and reducing emissions is just the beginning. In the future, increasing productivity will be the most critical trend for the off-highway industry.
In the next 35 years, 2.2 billion people will be added to the world’s population, and about 70% are expected to live in urban areas. The coming population explosion means farmers will need to produce more from every acre or hectare, and truckers will need to haul more goods. More buildings, roads, and infrastructure will need to be built in shorter timeframes.
In the meantime, emissions regulations will continue to become more strict. To better represent the true impact of real world off-highway emissions, actual duty cycles are now starting to be analyzed in every operating condition and stage of operation, from idle to peak output. These trends will drive a tremendous demand for improved productivity across the industry. Managing the segment growth and complexity at the same time is a monumental challenge.
Consider the many types of specialized off-highway equipment available today: excavators, graders, stationary generators, mining trucks, cement mixers, tractors, row croppers, and harvesters, just to highlight a few examples. Each is becoming more sophisticated every year. Then contemplate the various climates, altitudes, terrain, and operating conditions for each different application. Only by thoroughly understanding these variables can we engineer effective solutions to get more work done with less fuel and lower emissions.
Cutting parasitic losses
Many vehicle systems are designed to run at peak power. But when idling or running at less than full load, these systems are actually oversized, leading to lower fuel efficiency and higher emissions. The key is to size systems for the specific operating condition and develop smart control strategies to manage them. Advanced technologies allow downsized engines to deliver greater specific power and do more work while still meeting the transient operation needs demanded from the application.
For example, variable speed fan technology can reduce parasitic losses on engine power, which in turn, leads to improved fuel efficiency. BorgWarner’s variable speed Visctronic fan drives communicate with the engine’s electronic control unit, responding directly to the engine’s and vehicle’s needs based on engine temperature, engine speed, vehicle speed, or engine load. Even under dynamic conditions, the Visctronic system operates only when needed, reducing the average fan speed, and therefore parasitic losses, in any given duty cycle.
Using similar technology, BorgWarner’s heavy-duty controlled coolant pump directs coolant flow based on engine coolant or cylinder head temperature. By stopping or reducing flow in more common low-load conditions, parasitic losses are reduced. Because flow is varied based on engine need rather than engine speed, cooling is more precise and overall engine efficiency is improved. Together, variable speed fan drives and variable speed coolant pumps can improve fuel efficiency up to 5% over conventional technologies.
Downsizing engines with advanced boosting solutions—including BorgWarner’s variable turbine geometry, regulated two-stage, eBOOSTER and eTurbo turbocharging technologies—also improves fuel efficiency without compromising productivity. In addition, cooled exhaust gas recirculation (EGR) dilutes in-cylinder oxygen content, avoiding formation of emissions in the combustion process where they start. BorgWarner’s compact EGR modules—including the valve, cooler, and pipes—dissipate heat quickly and deliver the appropriate flow rate at all times. EGR technology can decrease NOx emissions inside the engine, reducing the demand for aftertreatment and providing the best compromise for total fluid consumption (including fuel and urea).
On many job sites, equipment may be on standby, burning fuel but not performing any work. An excavator may be waiting to fill a dump truck, truck convoys may be waiting in line to receive their loads, and in colder climates, operators may keep engines running to provide heat to the cabin. Stop/start and smart idle systems help save fuel, reduce emissions, and minimize wear, just as they do for passenger cars. BorgWarner’s permanently engaged starter, stop/start accumulator, and variable valve actuation technologies support the introduction of stop/start and smart idle systems on off-highway vehicles. In addition, positive temperature coefficient (PTC) heaters can be used to provide cabin heat while the engine is off.
For natural gas engines, improved ignition systems are required. BorgWarner’s dual coil ignition technology features a second coil to generate a continuous, extended spark for more reliable ignition, improved fuel efficiency and less spark plug wear compared with conventional multi-spark ignition systems.
Controlling and optimizing operating temperatures
To achieve optimal efficiency for off-highway vehicles, BorgWarner offers many technologies—in addition to fan drives and coolant pumps—designed to help each system quickly reach and then maintain its optimal temperature for improved productivity and lower emissions.
For smaller engines, BorgWarner’s pressure sensor glow plugs combine a highly efficient glow plug with an integrated pressure sensor to monitor the constantly changing pressure inside the combustion chamber, warming the engine for fast starts in the coldest weather.
For larger engines, BorgWarner’s intake air heaters warm the engine for quick, reliable cold starts with lower emissions. Both technologies help optimize the combustion process, reduce variation from engine to engine as well as cylinder to cylinder, and contribute to reduced NOx emissions and PM.
Optimizing heat within the cabin not only improves driver comfort but can help reduce parasitic losses. BorgWarner’s PTC cabin heaters deliver instant heat and provide the same level of passenger comfort without running the engine. Especially effective in hybrid vehicles, PTC heaters can also be used in zonal cabin heating, which delivers heat directly to the operator instead of losing heat to other locations in the system.
Delivering durable solutions
In the off-highway industry, machines must be available on demand and run for thousands of hours with maximum durability and reliability. In addition to improving fuel efficiency and reducing emissions, down time for repairs and maintenance have a direct impact on productivity. State-of-the-art corrosion-resistant materials, fewer wearing parts, and advanced manufacturing processes are critical.
BorgWarner takes a collaborative approach to understanding the duty cycles and operating environments of off-highway vehicles. Achieving high engine efficiency across all operating modes—not just normal work modes—requires optimizing every system for a variety of conditions.
From variable speed fan drives and coolant pumps to turbochargers and EGR systems to electronically controlled thermostats and pressure sensor glow plugs, BorgWarner delivers innovations designed to cut parasitic losses, control operating temperatures, and optimize engine efficiency.
Brady Ericson, President and General Manager, BorgWarner Emissions Systems, and Daniel Paterra, President and General Manager, BorgWarner Thermal Systems, wrote this article for SAE Off-Highway Engineering.