JSMEA Prodacts and technology development projects

Silencer with waste-heat recovery capability
In addition to reducing noise, Hi Eco Silencer
cuts fuel consumption, CO2 emissions at the same time!
Introduction

To reduce operating costs and arrest global warming, the shipping
industry is, as with other fields of business, taking various actions
to save energy. Presently, however, waste heat from main power
generators is not recovered at all; it is released in the air untreated.
As such, Taiko Engineering Co., Ltd. has added a new functionof recovering waste heat (economizers) to its silencers for diesel
engines the company’s flagship product—7,300 units of which havebeen delivered to date. With the new capability, the Hi Eco Silencer
can now recover waste-heat energy with high efficiency from main
engines and make effective use of it. Consequently, fuel consumed
in auxiliary boilers can be reduced quantitatively, leading to curtailing
operating costs and greenhouse gas (GHG) emissions.

Steam supply systems for ships at anchor

Contrasted in Chart 1 are conventional and waste-heat recovery
systems in which steam is supplied while ships are at anchor.
Chart 1

Steam
supplysystems

BurnerSteamUsed formachinery/equipment

Auxiliary boiler system

Steam
Used formachinery/equipment
Used forcrewmembers

Used forcrewmembers

Auxiliary boiler system

Main generator engine

Main generator engine(1) Conventional system
A conventional steam supply system, which generates steam byworking an auxiliary boiler, is described on the left side of Chart 1. In
this system, all waste-heat energy from the main power generators
is released in the air, because the silencers are not capable ofrecovering exhaust heat.
(2) Waste heat recovery system
Shown on the right is the steam supply system with a silencer,
which Taiko Engineering has developed, that is capable of recovering
waste heat. Heat-transfer tubes (heat exchangers) in the silencers
function to recover energy from waste heat (and generate steam),
enabling users to obtain a sufficient quantity of heat (steam) that canbe used for on-board comforts for crewmembers and other purposes.

Features of Hi Eco Silencer(1) Recovers waste-heat energy and turns it into steam for reuse.
(i) Curtails fuel costs for using auxiliary boilers.
(ii) Reduces carbon dioxide (CO2) emissions.
(2) Capable of recovering waste heat.
(i) Saves space as users no longer need to have both silencers
and waste-heat recovery instruments.
(3) Adopts a water-tube system for exchanging heat.
(i) Achieves higher efficiencies (higher heat-recovery rates).
(ii) Reduces pressure losses (an advantage when scrubbers
and others are added)

Results of on-board tests for Hi Eco Silencer

When construction work was completed for installing Hi EcoSilencers, Taiko Engineering made sure that machinery andequipment, plumbing, meters and other parts and components
were all working properly. After that, it started power generators,
auxiliary boilers and other existing machinery and equipment onboard a vessel, and activated the waste-heat recovery silencers.
The company then conducted on-board tests while confirming
there were no problems adapting the Hi Eco Silencer to an existing
steam system. Immediately after the installation work, the first onboard test was carried out. In a period of two years, the company
visited the ship a total of seven times to takemeasurements for changes made over time inperformance, fuel reduction and other aspects.
As a result of investigating the quantity of fuel oil
consumed in boilers from the vessel’s log book,Taiko Engineering learned that the ship with Hi EcoSilencers installed consumed 0.8 kiloliters of fuel oil
per day, a reduction of 0.4 kiloliters from 1.2 kiloliters
used without the waste-heat recovery silencers.
<Results of on-board tests>
Chart 2(1) Quantity of steam generated
The numerical performance target of 100 kilograms per hour or more
was cleared. Taiko Engineering also confirmed that applying sootblowers was effective to lessen secular changes.
(2) It confirmed that the Hi Eco Silencer performed even higher
than needed to achieve the goal of reducing pressure losses to 1.5
kilopascals or lower and attenuations to 15 decibel A or lower.
(3) With reductions in fuel costs for operating auxiliary boilers, theinitial costs for installing Hi Eco Silencers can be recovered in aperiod of three to five years (depending on ship type).
Taiko Engineering is deeply grateful to Japan Ship Machinery andEquipment Association (JSMEA) for helping it develop the Hi EcoSilencer with financial support from The Nippon Foundation.

TAIKO SANGYO CO., LTD.
Contact: 9515-1,Mukaishima-cho,Onomichi-shi,Hiroshima Japan
Tel.: +81-848-44-5000 Fax: +81-848-44-5779
http://www.taiko-jpn.com
Jsmea News No. 110

19