The significance of energy saving in construction machinery
January 2, 2024 Hawk
(1) Energy crisis and air pollution
Since 1993, China has become a net oil importer. In 2013, the net import of crude oil reached 292 million tons, and its external dependence was as high as 58% . The “BP World Energy Statistics 2011” survey report released by BP Oil Company pointed out that China’s total primary energy consumption in 2010 was 2.432 billion tons of standard oil, surpassing the United States’ 2.286 billion tons of standard oil, and has become the world’s largest. energy-consuming countries. Research data shows that on the one hand, the process of discovering new oil reserves is relatively slow, but on the other hand, oil consumption is showing a higher growth rate; if the newly discovered oil reserves and their consumption follow the current trend, then The world’s oil resources will only be available until 2038. Due to our country’s special geographical location, the oil problem is more serious than that of other developed countries.
From the perspective of environmental protection, the amount of engine emissions is positively correlated with fuel consumption. Fuel internal combustion engine vehicles consume a large amount of petroleum resources and at the same time pollute the environment. They emit carbon, nitrogen, sulfur oxides, and other harmful emissions. Chemicals have become the main source of urban air pollution.
(2) Increasingly stringent emission standards
Looking internationally, the United States has implemented Tier 4 emission standards for non-road emission standards, and the European Union has also implemented Euro IV emission standards. The Ministry of Environmental Protection of my country also issued the “Emission Limits and Measurement Methods of Exhaust Pollutants from Diesel Engines for Non-road Mobile Machinery (China Phase III and IV)” (GB20891-2014)  in May 2014, and stipulated that since The third phase of emission requirements will be implemented on October 1, 2014, to further reduce the pressure on the environment caused by the increasing ownership and use of such machinery and equipment.
(3) Construction machinery has high fuel consumption and poor emissions
Engineering machinery is the second largest user of internal combustion engine products after the automotive industry. Due to the large engine displacement and high fuel consumption, the emission standards are more relaxed than those in the automotive industry, and environmental pollution is more serious than other industries using internal combustion engines. Statistics show that pollutant emissions from diesel engines of non-road machinery, mainly construction machinery, account for 38% of the total emissions nationwide . Taking a certain model of 20t excavator as an example, the fuel consumption per hour is about 20-30L, which is equivalent to the fuel consumption of a car driving 300-450km; during the same period of normal operation, the exhaust gas emissions of a 20t excavator The amount is equivalent to the exhaust emissions of 30 small cars. Therefore, the construction machinery industry has an extremely important responsibility for energy conservation and emission reduction.
In line with the “Opinions on Strengthening Energy Conservation and Emission Reduction in the Internal Combustion Engine Industry” issued by the General Office of the State Council in 2013, in response to the development trends and goals of internal combustion engines, in two years, more than 60% of internal combustion engine products will need to use environmentally friendly and energy-saving internal combustion engines, which will consume less fuel than the currently used internal combustion engines. dropped by more than 6%, and the noise was reduced to a certain extent.
(4) Energy conservation and emission reduction are in line with the national development plan
In the “Twelfth Five-Year Plan” industrial development plan issued by the China Construction Machinery Industry Association, “researching energy-saving technologies for engineering machinery products and research on energy diversity technologies for engineering machinery products” is an important development goal for breakthroughs during the “Twelfth Five-Year Plan” period. During the “Twelfth Five-Year Plan” period, energy conservation, emission reduction, and green manufacturing achieved fruitful results. In terms of energy-saving technology, we achieve energy savings of 5% to 12% for wheel loaders and 5% for hydraulic excavators. In terms of weight reduction technology, scientific research results have been achieved in loaders, forklifts, and other products that reduce the weight of the entire machine by 5% to 8%. Breakthroughs have been made in scientific and technological research on vibration and noise reduction. The overall noise of the loader has been reduced to 72dB, and the overall noise of the hydraulic excavator has been reduced to 71dB, reaching the international advanced level. The comprehensive energy consumption per unit of industrial added value in the entire industry dropped from 0. 0758t standard coal/10,000 yuan in 2010 to 0. 0688t standard coal/10,000 yuan in 2014, maintaining an overall downward trend. Therefore, in the “Thirteenth Five-Year Plan” industrial development plan released on March 28, 2016, green energy-saving products will continue to be listed as one of the nine categories of innovative products that the industry needs to focus on developing during the “Thirteenth Five-Year Plan” period, striving to “During this period, my country’s construction machinery has been upgraded in quality and efficiency, industrial energy consumption intensity has dropped, and the comprehensive utilization rate has increased significantly. Therefore, in the long run, energy-saving and environmentally friendly construction machinery will be the basic factor for its entry into the market. Construction machinery energy-saving technology will bring significant economic and social benefits to the country, society, and even users.
(5) The importance of hydraulic excavators in the construction machinery industry
As the most important construction machinery in engineering construction, hydraulic excavators undertake many types of work and have long working hours. As one of the important engineering machinery for national infrastructure construction, hydraulic excavators have been widely used in construction, transportation, water conservancy, mining, and military fields. About 65% to 70% of the earthmoving volume in various earthmoving projects in the world is completed by hydraulic excavators. Therefore, both the excavator’s powerful multi-functional adaptability and its huge development potential around the world reflect its important position in construction machinery. Therefore, the energy-saving and emission reduction of hydraulic excavators have attracted widespread attention and attention. The working conditions of hydraulic excavators are complex and the load changes drastically. According to research reports, in hydraulic excavators, the utilization rate of the engine’s output energy is only about 20%. The hydraulic excavator is a typical engineering machinery with the most complex working conditions, and its various energy-saving technologies provide a reference for the energy-saving research and application of other engineering machinery. Therefore, this book will focus on hydraulic excavators and cross-introduce loaders, forklifts, cranes, and other construction machinery.
To sum up, the energy-saving technology of construction machinery has become an important indicator to measure its advancement. For a long time to come, energy conservation and emission reduction will become an important research direction in the construction machinery industry. Against this background, the state has implemented some technical rectification systems for construction machinery companies in terms of environmental protection, mainly focusing on the upgrade of emission standards and the use of new energy. The research and development of environmentally friendly products has been related to the survival and development of enterprises. Engineering machinery companies have begun technological upgrading around energy conservation and emission reduction. At the same time, China’s construction machinery industry has begun technological upgrading and innovation, and environmentally friendly and energy-saving products are the future development direction.
In addition, a common feature of many construction machinery is to use a working device of a certain weight to lift the material to a specified height and then unload it. Using multi-way valves to control the working device to frequently lift and lower will waste a lot of energy. There are also some mechanisms, such as The loading mechanism of the excavator frequently accelerates, starts, and decelerates. If the potential energy accumulated after the working mechanism is lifted and the kinetic energy of the turntable braking can be recovered and utilized, it will be very beneficial to improve the energy efficiency of the engineering machinery. It is the current engineering machinery Hot topic in energy-saving technology research. Studying the power energy-saving technology and hydraulic energy-saving technology of engineering machinery, supplemented by energy recovery technology, can comprehensively improve the energy-saving performance of the entire machine, and it has very important practical significance for the energy-saving research of the entire machine.