The driver releases the accelerator pedal and keeps the clutch engaged. The forward kinetic energy of the truck reacts to the drive system and the engine to keep it running. The piston continues to reciprocate. The four strokes of intake, compression, expansion, and exhaust continue to circulate. At this time, once the engine exhaust valve braking (EVB) is started, the engine exhaust valve will be opened by the high exhaust back pressure, and the compressed high-pressure air will be discharged through the exhaust system, thereby reducing the high pressure air in the expansion stroke. The work done by the piston makes the engine change from a device that outputs power to a device that consumes power (like an air compressor), which consumes the kinetic energy of the entire vehicle to achieve the purpose of controlling or reducing the speed of the vehicle.
Propylene glycol is an important raw material for unsaturated polyester, epoxy Resin, and polyurethane resin. The amount in this area accounts for about 45% of the total consumption of propylene glycol. This unsaturated polyester is used in large quantities for surface coatings and reinforced plastics.
Propylene Glycol,Mono Propylene Glycol,PG 99.5% HENAN JINHE INDUSTRY CO.,LTD , https://www.hncarbonblack.com
April 10, 2023