前言
前言Foreword
鋁的導(dǎo)熱性能在金屬中排名第三,僅次于銀和銅,它的W/ (m X k)值可達(dá)到193,是10#碳素鋼(46.4)的4.16倍;它的重量很輕,比重2.71g/cm ,是10#碳素鋼的(7.8g/cm )的約三分之一。
鋁的耐腐蝕性能高于鐵,尤其是添加了一定量的其他金屬后,它的抗氧化、抗老化(鹽霧試驗(yàn))性能,可達(dá)到10#碳素鋼的5倍以上。
鋁的加工性能非常優(yōu)越,它可以通過(guò)熱擠壓工藝制成單根超長(zhǎng)的無(wú)縫鋁管,避免了用鋼管作為換熱芯體進(jìn)行焊接而產(chǎn)生的缺陷,可以避免鋼的高報(bào)廢率,因而以鋁代鋼,它具有以下優(yōu)點(diǎn):
1.因?yàn)樗鼘?dǎo)熱系數(shù)比10#碳素鋼高了4倍,所以在同等條件下鋁合金的換熱效果比10#碳素鋼更佳,其性價(jià)比更高;
2.在防水垢問(wèn)題上鋁合金管要好于鋼管、鋼管換熱器的盤管是碳鋼經(jīng)過(guò)熱浸鋅處理過(guò)的,其表面很粗糙容易結(jié)水垢,日積月累后水垢會(huì)越來(lái)越厚,會(huì)嚴(yán)重影響盤管的換熱效果,即使我們也標(biāo)配有電子水處理器,但其效果也不是很明顯,而鋁合金管表面很光滑不容易結(jié)垢,且鋁的熱膨脹系數(shù)遠(yuǎn)大于鋼管,即使鋁合金管表面產(chǎn)生水垢也會(huì)在水淋狀態(tài)下自行剝離脫落,會(huì)大大增加盤管機(jī)芯的使用壽命,確保換熱效果不受影響;
3.10#碳素鋼經(jīng)過(guò)僅200小時(shí)的耐腐蝕試驗(yàn)就銹跡嚴(yán)重,使用壽命大概在2—4年,但防銹鋁合金卻可以通過(guò)6000小時(shí)的耐腐蝕試驗(yàn),其使用壽命可達(dá)到5年以上;
4.目前在行業(yè)里蒸發(fā)式冷凝器的排管焊接有兩種方法:(1)用彎頭與直管焊接,整個(gè)機(jī)芯盤管就有無(wú)數(shù)個(gè)焊接接頭,(2)用鋼帶卷成圓管進(jìn)行焊接,整個(gè)機(jī)芯盤管從頭到尾都有一條焊縫,焊縫處最容易腐蝕,所以鋼管機(jī)芯焊接位置最容易泄露,因焊接位置貫穿整個(gè)機(jī)芯,如機(jī)芯中間泄露則無(wú)法進(jìn)行修補(bǔ),我公司自行生產(chǎn)的鋁合金管單管可達(dá)150m長(zhǎng),其長(zhǎng)度足夠一次彎曲成型使用,因此單管中間無(wú)焊縫,焊接位置只在集流管上,都在機(jī)芯外側(cè),因此即使焊縫處泄漏,也可隨時(shí)補(bǔ)修;
5.由于蒸發(fā)冷安裝經(jīng)常放置到屋頂位置,有些大功率的蒸發(fā)冷設(shè)備自身重達(dá)10多噸,放在屋頂?shù)脑?,建筑往往達(dá)不到承重要求而需要進(jìn)行加固,耗資甚巨,但防銹鋁合金管做的蒸發(fā)冷重量只是鋼管的60%左右,重量大大減輕,放置在屋頂?shù)脑挻蠖鄶?shù)建筑無(wú)需加固,即使要加固的話工程量也很小可以省去很多時(shí)間和資金。
Foreword
The thermal conductivity of aluminum is ranked third in the metal,after the silver and copper, its W/(m X K)value can reach 193,is 10# carbon steel(46.4)4.16 times; it is light in weight, the proportion of 2.71g/cm ,10# carbon steel(7.8g/cm )of about 1/3.
Aluminum corrosion resistance than iron,especially added a certain amount of other metals, its antioxidant,anti-aging(salt fog test)performance,can reach more than 5 times the 10# carbon steel.
Processing properties of aluminum is very superior,seamless tubeswhich can be single long made by hot extrusion process,avoids the defects caused by welding steel pipe as heat exchange core body,canavoid high scrap steel,thus with aluminum and steel,it has the following advantages:
1. because of its thermal conductivity than 10# carbon steel high 4 times,so the heat exchange efficiency of aluminum alloy under the same conditions than 10# carbon steel is better,the price is higher;
2.in the water fouling problem of aluminium alloy pipe is better than steel pipe, coil heat exchanger tube is carbon steel after hot dip zinc treated, the surface is very rough easy scaling, after days and months multiplyingscale will be more and more thick, will seriously affect the effect of heat exchange coil,even though we also comes standard with electronic waterprocessor,but its effect it is not obvious.a(chǎn)nd the aIuminum alloy tubesurface is very smooth and not easy to scale.a(chǎn)nd the aIuminum thermal expansion coefficient is much larger than the steeI pipe.a(chǎn)lumjnum alloytube surface even produce scale willbe in the water state to peel off,wilI greatly increase the service life of the coll core,Ensure that the heating effect is not affected
3.1 0#carbon steel corrosion test after only 200 hours of rust seriously,service life is about 2-4years,but the antirust aluminum alloy can be acorrosion test for 6000 hours,its service life can reach more than 5 years;
4.is currently in the industry of evaporative condenser pipe welding in two ways:(1)with the elbow and straight pipe welding,the entire core coilhas a welded joint,(2)are welded steel pipe to form a round,the whole movemenf from A to Z coil has a weld,weld the most prone to corrosion,so steel core welding position most easily leak,because the welding position throughout the movement,such as the core intermediate leakscannot repair,aluminum alloy our company’s own production tubes up to 150m long,and the length of a bending forming enough use, because there is no weld this pipe,welding position only in the manifold,inmovement outside,so even if the weld leakage,but also can repair;
5.due to evaporative cooling instailation often placed in the position of the roof.the evaporative cooling equipment and some high power selfweighing more than 1 0 tons,on the roof,the building cannot reach thebearing requirements and needs strengthening.expensive,but theantirust aluminum alloy tube evaporative cooling steel tube weight is onlyabout 60%,weight greatly reduced,placed in the roof of the words most building without reinforcement.construction quantity if reinforcement is also very small can save a lot of time and money.