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液压系统“高效冷却净化”一体化技术研究

日期:2017年7月27日 15:14

  对于液压和润滑系统,油液的过热和 污染造成机械设备产生故障的重要原因。污染造成液压 系统的故障已逐渐被认识,而油温过高的 危害尚未引起足够的重视。液压系统总效 率通常只有50%~70%,所以“发高烧”是液压系统的 通病之一。

  液压系统的油 温过高会造成许多危害,例如:使油液粘度下降,系统容积效率降低,加剧温升,造成恶性循环;使密封圈强度降低,同时促进橡胶的老化,降低机器的可靠性;加速油液的氧化,缩短使用寿命。

  所以,研究强化传热 技术和高效净化技术,研制体积小、效率高,能够同时降低 油温净化系统的冷却净化产品对提高液压系统、润滑系统的可 靠性和机械设备的使用寿命具有普遍的意义。

   In the hydraulic and lubricating system, the excessive heat and pollution of the oil can cause the failure of mechanical equipment.The fault of the hydraulic system has been gradually recognized, and the danger of excessive oil temperature has not been paid enough attention.The total efficiency of hydraulic system is usually only 50%~70%, so "high fever" is one of the common diseases of hydraulic system.Excessive oil temperature of hydraulic system can cause a lot of harm, for example, reduce oil viscosity, reduce system volume efficiency, aggravate temperature rise, create a vicious circle;Reduce the strength of the sealing ring and promote the aging of rubber and reduce the reliability of the machine.Accelerate the oxidation of oil, shorten the service life.So, the heat transfer enhancement research technology and efficient purification technology, development of small volume, high efficiency, to reduce the cooling oil temperature purification system at the same time to purify a product to improve the reliability of hydraulic system, lubricating system and the service life of mechanical equipment has universal significance.Tube and shell heat exchanger of flow and heat transfer experiment on the oil cooling tube and shell heat exchanger, the widespread use of shell side flow heat transfer is a weak link for many years, the shell side of strengthening heat transfer of the most common method is to add ribs on the outside of the pipe, in order to increase the shell side of heat exchange area of progress in order to restrict the flow of fluid to strengthen shell heat exchanger, people use a variety of block flow board to enhance the heat transfer, use morer is e. straight cover panels or bow.They allow the flow of the shell side medium to flow across the tube bundle, and make a tortuous motion, so as to increase the local mixing of the fluid and deepen the turbulence and make full contact with the pipe wall to realize the enhanced heat exchange.

  管壳式热交换 器的流动与强化传热实验研究Experimental study on heat transfer and flow of tube - shell heat exchanger.

  对油液冷却普 遍使用的管壳式热交换器而言,壳侧油流的传 热是个薄弱环节许多年来,壳侧强化换热 最普遍的方法是在传热管外侧加肋,以增大壳侧换 热面积为了进步限制流体流动来强化壳则换热,人们采用各种 各样的挡流板来增强换热,用得较多的是 直挡流板或弓形挡流阪。它们使壳侧介 质的流动横穿管束,作曲折运动,使流体局部混 合加强和紊流度加深并与管壁充分接触,来实现增强换热。

     For oil cooling tube and shell heat exchanger, the widespread use of shell side flow heat transfer is a weak link for many years, the shell side strengthening heat transfer of the most common method is to add ribs on the outside of the pipe, to increase the shell side of heat exchange area of progress in order to restrict the flow of fluid to strengthen shell heat exchanger, people use a variety of block flow board to enhance the heat transfer, use morer is e. straight cover panels or bow. They allow the flow of the shell side medium to flow across the tube bundle, and make a tortuous motion, so as to increase the local mixing of the fluid and deepen the turbulence and make full contact with the pipe wall to realize the enhanced heat exchange.

  Gupta等在用玻璃制 造的小型热交换器榷型上用示踪小球作了壳侧流动的显示研究。Berner在有机玻璃壳 体中用注入示踪液的方法和铝示踪球的方法观察了流体流经挡流板的情形。Murray用注入示踪液 的方法观察了流体流经管束的流型并测试了流阻。

    Gupta et al. used a small heat exchangers made of glass to discuss the display of the shell side flow with the tracer ball. Berner used the method of injecting tracer fluid and aluminum tracer in the organic glass case to observe the flow of the fluid through the baffle plate. Murray observed the flow of the fluid through the tube and tested the flow resistance by injecting the tracer.

  ①流型显示实验研究Flow type display experimental study.

  流型显示实验表明,示踪液在直挡 流板附近形成明显的相对涡流滞止区,不利于热交换 螺旋板可消除涡流滞止区,延长流体的流程,利于强化传热;在螺旋板流道 中加多孔介质,对流动的扰动很大,在很低雷诺数 下就形成紊流,而且使流动分市均匀,对张化传热很削。

   Flow pattern according to the experimental results show that tracer fluid flow in straight plate forming obvious relative eddy near stagnation zone, does not favor the spiral plate heat exchanger can eliminate vortex stagnation zone, extend the fluid flow, heat transfer enhancement for; The turbulent flow is formed at very low Reynolds number, and the flow distribution is uniform, and the heat transfer is very thin.

  ②阻力实验结果Resistance experiment result

  对壳侧设置螺 旋板螺旋板中加多孔介质等不同壳侧结构的热交换器,在不同流量下 进行了壳侧流动的进出口压差测定,并研究其阻力特性。

In this paper, the pressure difference of the shell side of the shell side is determined by the heat exchangers with different shell side structures, such as porous media, and the resistance characteristics are studied.

  规,螺旋角。为3045在=对时,产的压力降最小,显然这是最佳 的螺旋板角度。在螺旋板流道 中充填多孔介质的量由孔隙率流道总体积多孔介质体积流道总体积定义由降增幅不大,但孔隙率为0.977时,压力降急剧增加。可,在螺旋板流道 中充填多孔介质的孔隙率为。985坫较合理的

The pressure drop is minimized for 3045 at =, which is obviously the best Angle of the helix. The volume of the filling porous media in the spiral plate flow channel is defined by the overall volume of the volume flow of the porous media volume of the porous media. The overall volume of the volume flow of the porous media is small, but the porosity is 0.977, and the pressure drop is increased sharply. However, the porosity of filling porous media in the spiral plate runner is. 985 drills are reasonable.

  ③管壳式热交换 器的传热性能实验研究 Experimental study on heat transfer performance of shell heat exchanger. 

  从5种不同壳侧结 构的换热性能测试结果(见)看出,其传热效果从 高到低依次排序为螺旋板(螺旋角U= 40*加多孔介质()=0.985)、螺旋板(U=40*直挡流板(板间距S=50mm)、直挡流板(S=100mm)加多孔介质(=0.985)、栽一雷诺数/fe 2高梯度磁过滤 技术研究磁场对铁磁性污染颗粒的吸引力是磁过滤器性能的决定性因素,磁场中污染颗 粒的受力导率,H/m;X*,为油液的磁导率,H/m;H为外磁场强度,A/m;gradH为该点的外磁 场强度的梯度,A/m2.从式(1)可以看出,铁磁性颗粒所 受的吸引力与外磁场强度H成正比,与磁场强度的梯度gradH成正比传统式 磁过滤器都是通过提高外磁场强度H来提高磁引力,从而提高过滤能力的;高梯度磁过滤 器则是通过磁介质的手段,主要提高磁场的梯度gradH来增大吸引力,获得高效滤除 污染物的效果在磁场中布置聚磁性多孔介质,会使磁介质附 近的磁场H和磁场梯度gradH比没有磁介质 时大很多。

From five different shell side of the structure of the heat transfer performance test results (see), the heat transfer effects from high to low in turn order for spiral plate, spiral Angle U = 40 * add porous medium () = 0.985) spiral plate (U = 40 * straight block flow plate (plate spacing S = 50 mm) straight block panels (S = 100 mm) and porous medium planted a Reynolds number (= 0.985)/fe 2 high gradient magnetic filtration technology research field of the attraction of the ferromagnetic particles is the decisive factor, the performance of magnetic filter pollution particles in magnetic field, the stress of the conductivity, H/m.X*, the permeability of oil,H/m;H is external magnetic field intensity,A/m;GradH for this point of the strength of the external magnetic field gradient, A/m2) can be seen from the type (1), ferromagnetic particles of attraction is proportional to the external magnetic field intensity H, is proportional to the magnetic field 

  尤其是gradH与磁介质截面直径d成反比,当d很小时,gradH的值可以很高 所以基于此原理的高效磁过滤器也称为高梯度磁过滤器3多孔介质强化 传热和高梯度磁净化一体化的兼容性和互惠性结合多孔介质强化传热和高梯度磁净化技术,油流中的多孔 介质能够显着增加对流动的扰动,破坏边界层,强化传热;同时,多孔介质能大 大提高磁场的梯度,从而提高磁净 化器的性能,说明两者结合 具有良好的兼容性其互惠性还表现在控制温度对永久磁铁的影响和粗糙换热表面2个方面1降低永久磁铁的温度,利于提高高梯 度磁净化的效率考虑到工作的可靠性,液压润滑系统 的磁净化磁源一般都用永久磁铁,高梯度磁过滤 器工作时,过滤器的永久 磁铁和液压系统的油温相同在不同的温度下,永久磁铁的性 能有一定的变化,对磁过滤器的 效率将有明显的影响。

Especially gradH is inversely proportional to the magnetic medium section diameter d, when d is very small, gradH values can be very high so based on the principle of magnetic filter, also known as efficient heat transfer enhancement high gradient magnetic filter 3 porous medium and high gradient magnetic purification integration compatibility and mutual combination of heat transfer enhancement porous medium and high gradient magnetic purification technology, porous medium can significantly increase the flow of oil flow disturbance, destroy the boundary layer, enhanced heat transfer;At the same time, the porous medium can greatly improve the magnetic field gradient, thus improve the performance of magnetic filter, shows that it has good compatibility with the reciprocity of the combination also performance in controlling the temperature on the influence of the permanent magnet and rough heat exchange surface 1 lower the temperature of the permanent magnet, two aspects to improve the efficiency of the 

  永久磁铁的磁 性能受温度、时间以及应力 等环境因素的影响,其中以温度的 影响最为重要给出了铁氧体永久磁铁的饱和磁感应强度Ms体的磁性能随 温度的升高而下降。显然,研宄磁过滤器 的性能必须考虑温度因素的作用。

Permanent magnet magnetic can be affected by environmental factors such as temperature, time, and stress, of which the influence of the temperature of the most important gives a saturated magnetic induction intensity of ferrite permanent magnet magnetic Ms can drop with the rise of temperature. Obviously, the performance of the research magnetic filter must consider the function of temperature.

  1.对已研制的一 种处理高粘度齿轮油的高梯度磁过滤器在不同温度工作时的外壳端面中心处的磁场进行测试,结果表明,70℃时的磁场强度只有18℃的1 /4左右,见这个测试没 有考虑保温时间的因素,但已足以证明 高梯度磁过滤器的磁场受到温度的显着影响

To have developed a processing gear oil with high viscosity, high gradient magnetic filter shell when he worked in different temperature end face of the magnetic field center for testing, the results showed that only 18 around a quarter of 70 when the magnetic field intensity, as shown in the test did not consider the factor of heat preservation time, but is enough to prove that the high gradient magnetic field of magnetic filter affected by temperature significantly

  2.高梯度磁过滤 器磁场强度与温度的关系实现冷却和净化一体化,可将永久磁铁 布置在冷却介质中,保持磁铁低温,维持磁铁的高磁性,从而提高高梯 度磁净化的效率。

  3.粗糙换热表面,提高换热效率 磁净化捕捉的颗粒多为铁质磨损物,在冷却水管中 布置磁铁,部分颗粒必然 被吸附在冷却水管的外表面,这些在换热表 面上的颗粒能起到粗糙传热表面的作用,阻止附面层的形成,利于进一步提 高传热效率取出冷却管中的永久磁铁,污染颗粒失去吸附力,可以方便地实现清冼

  4.管壳式冷却净 化器的研制与性能测试结合多孔介质强化传热技术和高梯度磁净化技术,研制了管壳式 冷却净化器,其结构示意图 见聚磁性多孔介质是由非晶态软磁合金喷成的厚0.04mm,宽0.5mm的细长丝。其它兀件都用 不锈钢制造,避免对磁场的 影峋永久磁铁布置在水管及中心管中,相同的极面相对,使磁力线向外延伸,充分磁化聚磁 性多孔介质中心管中的磁铁和管壁的缝隙允许冷却水流过,使中心管兼作传热管,同时使永久磁 铁得到冷却过滤性能实验表明,同样条件下传 统磁过滤器对1(Mm以上颗粒的过 滤比只有1.38,相应过滤效率为27%而新研制的管 壳式冷却净化器对1(Mm以上的颗粒的 过滤效率为84%,可见冷却净化 器的过滤效率比传统磁过滤器高2.1倍新研制的管 壳式冷却净化器的 壳侧对流换热系数和现有产品的比较见是冷却净化器与SL307油冷器及TSO306油冷器的性能比较。在雷诺数2000时,冷却净化器的 壳侧对流换热系数T比SL307高19.7*,比TS306高3%.

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