27
Eylül
2013
international
construction
Türkiye
Verimlilik arayışı
İNŞAAT MAKİNELERİ
The company said that it is seeing fuel savings
in the region of 10% when compared to
previous generations. On a machine like the
22 tonne JS 220 tracked excavator working a
1,600 hour year, this could equate to savings
of US$6,750 over a three year period, based on
European diesel prices.
JCB has also recently launched a new six
cylinder Ecomax engine, the 672, which initially
is only compliant to Tier 2/Stage II emissions,
meaning that the machines it will power,
the JS330 and JS350, will only be sold in
developing regions of the world. A Tier 4 Final/
Stage IV version of this unit is expected to be
developed by mid 2015 for use in machines
destined for Europe and North America. It
is likely to have to be fitted with an SCR to
achieve this, but JCB is confident it will not
have to substantially change its engine bay
designs to accommodate it.
New technology
So even with traditional diesel engines, there
are significant differences between what
competing manufacturers can offer in terms
of on-board technology and fuel efficiency for
excavators.
But today there is a growing move towards
augmenting traditional power sources with
new systems to save even more fuel. The most
talked-about iof these s hybrid technology, and
this is an area where Japanese manufacturer
Komatsu has been a clear leader.
The company’s first hybrid excavators were
launched in 2008, and since then Komatsu says
it has sold more than 2,000 such 20-tonne
class excavators, logging more than 1 million
hours of work. The latest version, the 21.2
tonne HB215LC-1, was on display at bauma
and the company says it offers 25% less
fuel consumption and CO
2
emissions than a
traditional excavator.
The machine achieves this by capturing energy
that would otherwise be wasted in braking
slewing movements of the upper structure.
Instead of a brake, a generator is used to
convert this energy to electricity, which is
then stored in a capacitor. The energy is then
available to rotate the upper structure back
again or to assist the engine in other ways, as
dictated by the on-board computer.
The use of capacitors - sometimes also
called super capacitors or ultra capacitors
– is an interesting one, given that hybrids in
the automotive industry have tended to use
more traditional batteries to store energy.
One advantage in using capacitors is that
they can discharge their energy more quickly
than a battery, which is more suitable to the
stop-start applications that are often found in
construction. They also have weight and size
advantages over batteries, and can accept and
deliver high currents.
Komatsu is the only manufacturer to have
an electrical hybrid excavator in production
today, although other manufacturers, including
Doosan, Hitachi and Hyundai, have exhibited
prototype 20 tonne class hybrid excavators at
various exhibitions over the last few years.
But there has not been a great flood of such
>
Komatsu, ilk melez tahrikli ekskavatör modelini
2008’de piyasaya sürdü ve o günden bu yana, bu
teknolojiyle donatılmış 20 tonluk ekskavatörlerin
satış adedi 2.000’i aştı. Şimdiye dek 1 milyon saatten
fazla çalışan bu ekskavatörlerin en yeni versiyonu
HB215LC-1, Bauma fuarında görücüye çıktı. 21,2
ton ağırlığındaki makinenin, klasik bir ekskavatöre
kıyasla %25 daha az yakıt tükettiği ve CO2 saldığı
ileri sürülmekte.
Bunu sağlarken kullanılan yöntem, kule
kısmının dönüş hareketlerini frenleme esnasında
açığa çıkan ve normalde boşa giden enerjinin geri
kazanılması. Bu enerjinin elektriğe dönüştürülmesi
için, bir fren yerine jeneratör kullanılıyor ve üretilen
Liugong kuruluşu, 45 ton ağırlık sınıfındaki 945E’yi Bauma’da sergiledi. Makine, 280 kW’lık Cummins
QSM11 motoru tarafından tahrik ediliyor ve Tier 2 egzoz emisyon standardına uyumluluk sergiliyor
JCB, son olarak JS330 ve JS360 ekskavatörleri
için, bugüne kadarki ilk 6 silindirli dizel motoru
olan Ecomax 672’yi geliştirdi
enerji de bir kapasitörde depolanıyor. Bu enerji,
makine bilgisayarının yönlendirmesine göre,
daha sonra yine kulenin döndürülmesinde, veya
motora diğer görevlerde destek sağlanmasında
kullanılabiliyor.
Bazı kaynaklarda süper-kapasitör veya
ultra-kapasitör şeklinde de anılan kapasitörlerin
kullanımı, aslında ilginç bir konu. Zira, otomotiv
sektöründeki melez tahrikli modellerde, enerji
depolaması daha çok klasik aküler yardımıyla
gerçekleştirilmekte. Kapasitörlerin aküler karşısında
ortaya koyduğu avantajlardan biri, enerjiyi çok daha
hızlı boşaltabilmesi ve bu da inşaat çalışmalarında
sık sık meydana gelen dur-kalklı uygulamalar için
