Measures for sustainable development of concrete construction machinery 1
The use of construction machinery can not damage the living environment of human beings. This requirement is an inevitable trend. This has prompted us to improve and improve the technical quality of concrete construction machinery. If you only focus on reducing costs, while not paying attention to your own products, you will eventually influence the future of the product itself.
We believe that the current sustainable development technology of concrete construction machinery should focus on: 1 saving energy; 2 reducing pollution; 3 improving performance; 4 improving efficiency. This article focuses on energy conservation and pollution reduction.
1 Measures to save energy and improve engine exhaust pollution
Energy conservation not only has great economic benefits for users, but also helps protect the earth's resources and contributes to the sustainable development of human society. Saving energy and reducing pollution are closely related. The process of energy extraction, transportation, processing and use is the most polluting of the global environment. The harmful substances in diesel exhaust gas are mainly CO, HC, NOx, sulfur compounds and carbon particles. Generally, the carbon particles emitted by the diesel engine due to incomplete combustion are 30 to 40 times that of the gasoline engine.
At present, the state's control of motor vehicle exhaust emissions is gradually being promoted, and all types of motor vehicles that do not meet Euro II emission standards will not be allowed to enter large cities. The use of computer-controlled turbocharged intercooled diesel engines has unique advantages in reducing engine exhaust emissions, such as the VolvomFM12 engine. The computer-controlled fuel injection system is mainly composed of a sensor, an actuator and an electronic control unit; the electronic control unit is an engine computer or a central processor; the sensor has an intake air temperature and pressure sensor, a load sensing sensor, and an oil temperature and pressure sensor. Several types; the actuator is a single pump driven by a solenoid valve.
The signals sensed by each sensor are combined into an engine computer or central processor for comprehensive analysis, and then converted into control signals to control the optimal fuel injection amount, injection timing and intake air amount of the diesel engine. Some electronically controlled diesel engines can also analyze the composition and content of exhaust gas after combustion. When the combustion is not completely exhausted, the diesel engine can immediately adjust the concentration of the diesel mixture to eliminate this phenomenon in time.
Due to the use of turbocharged intercooling technology, the exhaust gas generated by the primary combustion is further purified by the exhaust gas recirculation system (EGR system) through secondary combustion, and the energy utilization rate is also improved, so that the fuel consumption of the engine is significantly reduced. This type of electronically controlled diesel engine can meet the emission standards of Euro II and above. Another significant advantage of computer-controlled diesel engines is their enhanced power output performance. When the load factor of the diesel engine changes, the computer can immediately feel and adjust the output of the diesel engine in time.
For engines without supercharged intercooler, an exhaust filter can be used to improve exhaust emissions. For example, an exhaust filter using a ceramic foam body and a wall flow type ceramic honeycomb body, or an exhaust filter based on the electrostatic particle trapping principle, has a good effect for capturing carbon particles in the exhaust gas; using zeolite as an adsorbent The exhaust filter has a good effect for absorbing the HC compound in the exhaust gas. In addition, the addition of anti-smoke additives to diesel fuel and the use of inferior diesel fuels containing heavy diesel fuel are effective measures to improve combustion efficiency and reduce pollutant discharge.
Another method is to properly limit the maximum power output of the engine. For example, the lOPE diesel engine of the Isuzu CXZ81Q truck has reached the Euro I emission standard in this way.
2 Measures to reduce engine and machine thermal pollution
The thermal pollution generated by a large number of various types of heat engines around the world is another important factor that deteriorates the Earth's ecological environment and climate. The greenhouse effect it produces has led to melting glaciers, rising sea levels, climate variability, and frequent occurrences of droughts and floods. The power machine, hydraulic circuit and some actuators of concrete construction machinery are all heat sources.
Therefore, reducing the thermal pollution of concrete construction machinery is also a problem that manufacturers should pay attention to. What can be done at present, such as the selection of the engine, should try to use an engine with high energy conversion rate and low heat consumption; in the design of mechanical moving parts (especially high-speed moving parts), friction should be minimized and lubrication should be strengthened. Hydraulic circuit design should minimize pipe flow resistance to reduce heat generation. But the most fundamental improvement has to wait for a new type of power machine to come out to replace the current heat engine.