Green design of hydraulic system

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Talking about the green design of hydraulic system

1, the green design principle of hydraulic system

this design principle is the basis of the technical principle, cost principle and ergonomics principle usually based on in the traditional hydraulic system design, but due to the continued downturn of the capital market, we cannot but temporarily withdraw the application for additional Issuance and incorporate it into the environmental principle, and put the environmental principle in a priority position. The principles of hydraulic system design can be summarized as follows:

(1) the principle of optimal utilization of resources

use less scarce or rare raw materials, try to find alternative materials, and use more waste materials, surplus materials or recycled materials as raw materials; Improve the reliability and service life of products; Try to reduce the types of materials in products, so as to facilitate the effective recycling of products after they are discarded

(2) the principle of minimum energy loss

try to use materials with good compatibility, and do not use materials that are difficult to recycle or cannot be recycled; On the basis of ensuring the durability of the product, give the product a reasonable service life, and strive to reduce the energy consumption during the use of the product

(3) zero pollution principle

try to use less or no toxic and harmful raw materials

(4) the principle of technological progressiveness

optimize the product performance, establish the design idea of "small and fine" in the structural design, and try to save the use of resources through the miniaturization of the product under the same performance, such as using light materials, removing redundant functions, avoiding excessive packaging, etc., to reduce the weight of the product; Simplify the product structure and advocate the design principle of "simplicity and beauty", such as reducing the number of parts, which is convenient for assembly, disassembly and classification after abandonment; Modular design is adopted. At this time, the product is composed of various functional modules, which is not only conducive to the assembly and disassembly of the product, but also convenient for the recycling and treatment after abandonment. In the design process, attention is paid to the variety and serialization of products; Adopt a reasonable process, simplify the product processing process, reduce the processing procedures, and simplify the disassembly process, such as adopting a connection method that is easy to disassemble in the structural design, reducing the amount of fasteners, and avoiding destructive disassembly as far as possible; Simplify the product packaging as much as possible and avoid secondary pollution

(5) the principle of the best overall benefit

consider the additional impact of the product on the environment, and provide information about the composition of the product, such as the type of material and its recycling performance

2. Green design strategy of hydraulic system

(1) working medium pollution control

hydraulic system - ideological pollutants, invasive pollutants and generated pollutants. In the process of product design, we should follow the principle of prevention first and treatment second, and fully consider how to eliminate pollution sources to fundamentally prevent pollution

in addition to reasonably selecting the parameters and structures of hydraulic system components, the following measures can be taken to control the impact of pollutants in the design stage. Install a fine oil filter before and after the throttle valve, and the accuracy of the oil filter depends on the requirements of the control speed. For all components and parts to be cut, the orifice must have a certain chamfer to prevent cutting the seal and facilitate assembly. All components and piping must be carefully cleaned after the processing process to eliminate burrs, oil stains, fibers, etc; Before assembly, the environment must be kept clean, and all components must be dry assembled. After assembly, choose a washing medium compatible with the working medium and clean it carefully. When it is put into normal use, the new oil should be added to the oil tank after static sedimentation and filtration. If the internal components are seriously worn in the system, an intermediate oil tank can be set up if necessary to precipitate and filter the new oil to ensure the cleanness of the oil

another aspect of working medium pollution is the pollution of the medium to the external environment. Try to use high viscosity working oil to reduce leakage; Realize the greening of the working medium of the transmission device of construction machinery as soon as possible, and use plain hydraulic oil; Develop the recycling technology of hydraulic oil; Develop green additives for working media, etc

(2) hydraulic system noise control

hydraulic system noise is a kind of pollution to the working environment, including mechanical noise and fluid noise. In the hydraulic system, the rotation speed of motors, hydraulic pumps and hydraulic motors is very high. If their rotating parts are unbalanced, periodic unbalanced forces will be generated, causing the bending vibration of the rotating shaft. When this vibration is transmitted to the oil tank and pipeline, it will make a lot of noise due to resonance. Dynamic balance test should be carried out on the rotor, and attention should be paid to prevent resonance during product design. Mechanical noise also includes high-frequency noise caused by mechanical parts defects and unqualified assembly. Therefore, the quality of manufacturing and installation must be strictly guaranteed, and the product structure design should be scientific and reasonable

in the noise of hydraulic system, fluid noise accounts for a considerable proportion. This noise is caused by the sudden change of oil flow rate, pressure, periodic change of flow, oil trapping and cavitation of the pump. Taking the hydraulic pump as an example, in the oil suction and oil pressure circulation of the hydraulic pump, periodic pressure and flow changes are generated, forming pressure pulsation, which causes hydraulic vibration and spreads to the whole hydraulic system through the oil outlet, At the same time, the pipelines and valve components of the hydraulic circuit reflect the hydraulic pulsating products, causing fluctuations in the circuit, resonating with the pump and generating noise. About 5% air is mixed in the open hydraulic system. When the pressure in the system is lower than the air separation pressure, the gas in the oil will quickly separate out in large quantities and form bubbles. When these bubbles encounter high pressure, they will be crushed and produce strong hydraulic impact. Therefore, when designing the hydraulic pump, the gear modulus of the gear pump should be taken as the small value, the gear should be taken as the maximum number, and the shape and size of the unloading groove should be reasonable to reduce the hydraulic impact; The determination of the plunger number of the plunger pump should be scientific and reasonable, and a triangular groove should be symmetrically opened on the oil suction and pressure valve plate to prevent the plunger pump from trapping oil; In order to prevent air from mixing, the oil suction port of the pump should be large enough and should be submerged to a certain depth below the liquid level of the oil tank, so as to prevent air from being sucked due to the decline of the liquid level after oil suction. In order to reduce the hydraulic shock, the closing time of the valve can be extended, and an accumulator should be set near the part prone to hydraulic shock to absorb the pressure wave; In addition, increasing pipe diameter and using hoses are very effective in reducing and absorbing vibration

(3) design of connection and disassembly of hydraulic components

the design of hydraulic system should try to improve the integration of hydraulic system. The principle is to optimize the functions of multiple components, realize the modularization of the system, and make the structure of hydraulic circuit as compact as possible, such as reducing the connection between hydraulic components, designing components that are easy to disassemble, etc. On the basis of meeting its functions, the focus of the design is the ground connection technology of hydraulic components. The complexity of assembly and disassembly of different connection structures is different. The complexity of assembly and disassembly of welded connection is the highest, which is easy to cause destructive disassembly of parts and components. The assembly capacity of screw connection is easy, and the degree of detachable programming is affected by the environment. If rust, it will lead to complex disassembly. The mechanical assembly of rivet connection is good, but the disassembly is complex, Human bite is a kind of connection method with better assembly and disassembly than at present, but the safety of its connection is reduced under the condition of high connection strength requirements

in order to make the hydraulic system more compact, according to the different installation types, the screw type elements can be made into various structural types; Valves with pipe connection and flange connection; The cartridge valve is convenient to combine several cartridge components into a composite valve. The ordinary hydraulic valve connected by plate can be installed on the manifold block, and the connection between oil circuits can be realized by using the holes on the manifold block, or the valve can be directly made into a superposition structure, that is, a Superposition valve. The Superposition valve has oil inlet and outlet ports and the interfaces of actuating elements, and its joints can be made into quick two-way joints to improve the assembly and disassembly

(4) energy saving design of hydraulic system

the energy saving design of hydraulic system should not only ensure the output power requirements of the system, but also ensure the economic and effective use of energy as much as possible. We are further strengthening the research and development of materials to achieve the purpose of efficient and reliable operation. The power loss of hydraulic system will reduce the overall efficiency of the system, increase the oil temperature, deteriorate the oil, and lead to the failure of hydraulic equipment. Therefore, when designing the hydraulic system, we must reduce the power loss of the system in many ways

in the selection of components, we should try to choose those components with high efficiency and low energy consumption, such as variable displacement pump with high efficiency, which can change the pressure according to the needs of the load to reduce energy consumption, choose integrated valve to reduce the pressure loss of pipe connection, choose proportional valve with small pressure drop and continuous control, etc

adopting various modern hydraulic technologies is also an important means to improve the efficiency of the hydraulic system and reduce energy consumption, such as pressure compensation control, load sensing control and power coordination system. Using the system of quantitative pump + proportional directional valve, multi pump (quantitative pump) + proportional throttling overflow valve, the efficiency can be increased by 28%~45%. Using the hydraulic circuit of theorem pump speed-up hydraulic cylinder, the overflow valve in the system plays a role of safety protection, And there is no overflow loss, and the oil supply pressure always changes with the load. This circuit has the characteristics of volume speed regulation and automatic pressure adaptation, which can significantly improve the efficiency of the system. (end)

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