An electric refrigerator system for Hino heavy duty trucks
Hino Motors, Ltd. (Hino) and DENSO Corporation (DENSO) have jointly developed the world’s first electric refrigerator system for heavy-duty trucks using a hybrid unit. This system is used in the Hino Profia, which will be released on Feb. 1, in Japan. With the combination of Hino’s hybrid powertrain system technology and DENSO’s electric refrigerator system technology, the two companies have developed a refrigerator system that helps improve fuel economy, improves refrigeration performance, and is quieter when operating.
Hybrid trucks conventionally use energy generated from hybrid systems to assist the vehicle’s driving. However, this new truck uses energy from hybrid unit only for the new electric refrigeration system, which saves fuel.
Heavy-duty refrigerated trucks typically require an auxiliary engine or need to use their main engine power to operate the compressor of the refrigerator. The newly developed electric refrigerator system uses energy generated while driving or regenerated energy from the hybrid unit to operate the refrigerator’s compressor. This substantially reduces the amount of fuel normally used to drive the engine to operate the compressor, thus reducing CO2 emissions as well.
Compared to refrigerated trucks that use an auxiliary engine to operate the compressor, the new system is quieter, and contributes to an approximately 150 kg weight reduction because it does not need an auxiliary engine.
In addition, compared with those having the main engine-driven compressor system, the new truck can operate the refrigeration compressor at a constant rotational speed using the energy supplied from hybrid system, which stabilizes the refrigeration performance and quality regardless if the truck is moving or stopped.
Trucks with main engine-driven compressor systems need to have separate refrigerator components in the engine compartment, under the floor panel, and in other places. However, the new truck uses a new integrated refrigeration unit that includes an electric compressor, condenser, and other devices. This simplified structure uses fewer tubes and wires and also is easier to maintain.
The new refrigerator system includes a stand-by unit that can be connected to an external 200-volt power source so the refrigerator temperature can be maintained while the engine off for a long period of time. The stand-by unit also has a timer function, which can pre-freeze the refrigerator room without the driver’s operation. This helps reduce fuel consumption and manpower costs.
The Hino Profia with an electric refrigerator system reduces the amount of fuel required to operate its refrigerator. The new truck’s fuel efficiency exceeds Japan’s 2015 fuel efficiency standards by 5 percent. Moreover, as standard features, the Hino Profia has advanced safety systems including an enhanced pre-crash safety system (PCS) designed to support drivers to prevent rear-end collision with vehicle in motion ahead, a lane-departure warning system that issues an alarm at a more appropriate timing, and a driver monitoring system that provides more precise detection. Thus, the new Hino Profia is a heavy-duty truck that achieves greater environmental and safety performance than before.
The compact and light-weight hybrid unit, installed to the Hino Dutro Hybrid with proven results in the market, was optimized as an energy source for this new refrigerator. This enables improved eco-friendly performance, while minimizing effects to load capacity and maintaining economy performance for the heavy-duty truck.
This is not obvious to me to reuse a hybrid unit which was not designed for this purpose to generate electricity for an electric refrigerator. Is the efficiency of the hybrid unit combined with the electric refrigerator really better than the one of a mechanical power transfer from a standard diesel engine? What about the added cost versus the fuel savings?