Recently, the foreign media Equipment World launched a series of reports on Future Fuels, aiming to discuss the evolution of diesel fuel alternatives that construction equipment and manufacturers around the world are experiencing, including hybrid power, battery power, fuel cell, and hydrogen internal combustion engine and hydrogen fuel cell technologies. The following is the third report in a series.
Ten years ago, heavy construction machinery and equipment manufacturers and heavy truck OEM manufacturers met the requirements of Tier 4 and Tier 4 final exhaust emissions. Try to improve air quality through different scientific and technological means to combat the impact of climate change.
It has been proved that the regulatory promotion of global emission regulations has brought technological upgrading and innovation, including hybrid diesel electric engines, which have made contributions to reducing fuel use and emissions.
In fact, when reducing fuel consumption and exhaust emissions, the carbon dioxide emissions will certainly decrease. What power can be expected to replace the traditional internal combustion engine?
If pure electric power and hydrogen fuel system are the forces that will shock the world in the future, then hybrid power and natural gas engine are the hope at present.
Hybrid power equipment covers almost all models
In order to overcome the shortcomings of traditional excavator direct drive power system, the power motor is introduced into the traditional direct drive power system as an auxiliary power source to form a hybrid power system with the engine to drive the load. In the hybrid power system, the power motor plays a crucial role in the energy saving and emission reduction characteristics of the system.
The diesel electric hybrid vehicle is similar to a kind of equipment with a small internal combustion engine. It uses the flywheel to provide power for the generator and battery power, and then provides power for the wheel, track and hydraulic system.
In addition, the size of hybrid equipment varies from the 3000 pound Toyota Prius to the 744,000 pound Caterpillar 798 AC mining truck.
For earthwork contractors, many diesel electric hybrid vehicles have been verified under actual working conditions, including Komatsu's HB215LC-1 hybrid excavator, John Deere's 644K electric hybrid wheel loader and Cat D7E bulldozer. Customers have given high comments on these hybrid power equipment, and the fuel economy can be improved by 25%~40%.
In addition to the above obvious fuel economy, hybrid construction equipment has many advantages. These advantages include:
1) The instantaneous response characteristics of the motor enable the hybrid electric equipment to operate at the optimal speed. Heavy excavation can be carried out without accelerating the engine or switching to power mode;
2) Traction control can be automatically adjusted, and there is no delay in acceleration;
3) The vehicle can recover energy through braking and regenerative braking when going downhill to provide power for the equipment;
4) Compared with traditional transmission, brushless motor and AC drive of hybrid power equipment do not need more maintenance.
Historically proven hybrid equipment
The telescopic boom forklift has proved to be particularly suitable for diesel electric hybrid models. In recent decades, these machines have been pioneering the field of hybrid power.
In 2017, JLG has ushered in the 20th anniversary of its hybrid technology release. As the product representative of JLG hybrid power, H800AJ arm type aerial work platform officially appeared, with a platform height of 24.4m and a working height of 26.4m. A motor/generator is equipped to provide electric driving force for the equipment, and the charging of this motor is performed by a Tier 4 Final diesel engine. (Click the title to learn about the product details: JLG (Jieerjie) appeared in 2017 CONEXPO to reshape the hybrid series product line)
In 2018, German engine manufacturer Doutz introduced an electric hybrid engine to replace the traditional 3.6-litre diesel engine. The company used a 2.6-litre engine to support Liebherr TL 432-7 telescopic arm fork truck, and a 2.2-litre engine to power Manitone MT1335 telescopic arm fork truck. According to the company, hybrid engines will account for 5%~10% of its market.
As with all electric building equipment, the electric power of hybrid power can supply power to other parts through fan belt, such as cooling fan, water pump, oil pump and PTO. However, under the action of electrification, the loading, lifting or driving of equipment does not consume electricity.
Both hybrid and all electric systems can be used with advanced control systems. "Electrification is a key driver of automation and autonomy," said Preston Moore, a planner and product manager for electrified drive systems and propulsion battery solutions at John Deere Power Solutions. "This can reduce the operating costs of the construction site for customers."
Electrification also improves the opportunity for data acquisition, as battery powered equipment generates more data than pure diesel equipment and provides deeper connectivity. Preston Moore said that it is possible to provide more convenience and more service models for after-sales service.
Hybrid equipment horsepower division
In fact, one of the driving factors behind the diesel electric hybrid power equipment is the result of OEM manufacturers' efforts to meet EPA emission regulations. Due to the technical differences between engines with more than 75 horsepower and engines with less than 75 horsepower, engines with more than 75 horsepower need more expensive exhaust aftertreatment devices. Less than 75 horsepower requires no post-treatment, so the cost is lower.
By comparing the product parameters of hybrid power, it is not difficult to find that the 75 horsepower engine is the dividing line, and skid steer loaders, small loaders and excavators less than 75 horsepower are easier to replace hybrid power. In other words, these devices can increase horsepower through battery power. Therefore, small equipment OEM manufacturers can still use the 75 horsepower internal combustion engine, and only need to increase the horsepower by 10% or 20% through the battery, without installing a larger, heavier and more expensive exhaust treatment system. Jeremy Carson, director of Cummins' off-road business, said.
"Hybrid power equipment has always been the focus of technology improvement," said Jacob Whitson, chief project manager of Calstart, "but given the progress in technology and regulatory structure in California, the demand for hybrid power will become less and less.
However, in the current situation, hybrid power may be a feasible solution.
Carson said that equipment buyers also need to pay special attention to the value and disposal of used hybrid equipment. A large proportion of used machines sold at American auctions are purchased by Latin American contractors, possibly up to 25 per cent.
Suppose that the contractors and equipment suppliers in Latin America above lose interest in hybrid power equipment. Considering the technical complexity of hybrid power and the imperfect supply chain of parts, these factors will not only affect the total cost of ownership of contractors, but also affect the total cost of ownership of large leasing companies.
In addition, contractors and dealers should pay special attention to the cost and service life of the battery in the hybrid power system. Most OEM manufacturers are exploring battery recycling programs and reducing the environmental impact of battery production. As with any other construction machinery and equipment, the Contractor must incorporate all aspects of cost factors into the operating costs of the entire life cycle of the equipment.
