 |
 |
 |
 |
No. 39 Nov. 2021
|
|
|
<Feature-Ⅰ>Energy and Environment |
|
|
| 1 |
Demonstration of Hydrogen Refueling Station Using
Renewable Energy for Fuel Cell Vehicles |
|
|
|
Dr. Akitoshi FUJISAWA, Shigeru KINOSHITA, Dr. Shin-ichi MIURA,
Sueki NAKAO, Fumiaki SUZUKI, Kazuhiro YAMASHITA
|
|
|
To significantly reduce CO2 emissions during the
production of hydrogen for hydrogen refueling stations,
it is effective to use water-electrolysis hydrogen
generated with renewable electricity. Kobe Steel has
devised a configuration to add a hydrogen generator
using a solid-polymer-electrolyte water electrolyzer (20
Nm3/h) and equipment for storing generated hydrogen
at a high pressure (45 MPa) to a standard hydrogen
refueling station (hydrogen supply capacity 300 Nm3/h)
and has designed and built a demonstration plant. The
demonstration included the operation of the water-electrolysis
hydrogen generator for about 780 hours with
the variable power source without any problems with
followability and durability. In addition, the function of
the entire system designed was verified by the operation
linked with the hydrogen refueling station. In the future,
further cost reduction and efficiency improvement will
be considered. It is necessary to set a social value for
hydrogen, which emits less CO2.
|
|
| 6 |
Utilization of Cold Energy in Intermediate Fluid-type Vaporizer (IFV) for LNG
Receiving Terminals |
|
|
|
Tomohiro SUZUKI, Shinji EGASHIRA, Yuji SUMIDA
|
|
|
Intermediate fluid-type vaporizers (IFVs), a type
of LNG vaporizers, have been used as vaporizers that
enable the utilization of the cold energy of LNG in, for
example, cryogenic power generation. Recently, there
is an increasing number of cold energy utilization
projects using chilled water from an IFV for, e.g., the
intake air cooling of gas turbines. This paper introduces
the latest trends in LNG receiving terminals including
offshore receiving terminals, the features of IFVs as LNG
vaporizers for cold energy utilization, and examples of
cold energy utilization using IFV including gas-turbine-intake
air cooling.
|
|
| 13 |
Expanding Application of Micro Channel Equipment (Diffusion Bonded Compact
Heat Exchanger; DCHE™)
|
|
|
|
Yasutake MIWA, Masataka AZUMA, Dr. Koji NOISHIKI
|
|
|
The demand for microchannel heat exchangers, a type
of compact heat exchanger, is expected to increase as
they are used in applications requiring light weight and
compactness and as apparatuses for offshore equipment.
Above all, their demand has been increasing in recent
years for use in the fuel supply systems of offshore
equipment that uses liquefied natural gas (LNG) and
small-capacity LNG vaporizers for satellite bases.
These applications require, not only pressure tightness
and compactness, but also measures to be taken against
the freezing of the fluid serving as the heat medium. In
the case of diffusion bonded compact heat exchangers
(DCHE™s), concepts having to do with the suppression
of freezing have been incorporated into their design,
and tests were conducted using liquid nitrogen and
LNG, to establish the design guidelines for the range
of vaporization performance and icing. This report
introduces the effort to apply a DCHE™ to LNG vaporizer
applications.
|
|
| 20 |
Large Capacity Reactor, Stacked Multi-Channel Reactor (SMCR™) for Flow Chemistry
|
|
|
|
Nobumasa ICHIHASHI, Tomohiro OZONO, Akira MATSUOKA
|
|
|
The stacked multi-channel reactor (SMCR™) is a
(continuous) flow chemical reactor that replaces the
conventional stirred bed reactors and has been developed
as a reactor capable of large-capacity processing. As
an effort after the development, an SMCR™ made of
metal has been added to the lineup and, furthermore,
a ceramic SMCR™ with high corrosion resistance
has been developed to expand the applications, for
which verification tests have been conducted against
thermal shock. Moreover, basic tests and bench scale
testing equipment have been actively commissioned
and implemented with the aim of promoting the
commercialization of SMCR™ in addition to equipment
supply. As for bench scale testing, a bench scale testing
apparatus installed in Kobe Steel performs verification
tests to verify the usefulness of SMCR™ units.
|
|
| 27 |
Compressed Air Energy Storage System
|
|
|
|
Hiroki SARUTA, Dr. Takashi SATO, Masatake TOSHIMA, Yohei KUBO
|
|
|
Large-scale power storage equipment for leveling the
unstable output of renewable energy has been expected
to spread in order to reduce CO2 emissions. The
compressed air energy storage system described in this
paper is suitable for storing large amounts of energy for
extended periods of time. Particularly, in North America,
China and other areas, where rock salt layers are widely
distributed, using underground spaces formed in the rock
salt layers to store compressed air can reduce the unit
kWh cost of equipment. The equipment's responsiveness
was obtained on the basis of the data for large-scale
demonstration equipment of 1 MW class, verifying that
the equipment can respond to commands within seconds.
This paper further describes the future development of the
compressed air energy storage system.
|
|
| 33 |
This paper was originally written in January 2020
MIDREX® Process: Bridge to Ultra-low CO2 Ironmaking
|
|
|
|
Dr. Vincent CHEVRIER, Lauren LORRAINE, Haruyasu MICHISHITA
|
|
|
Midrex Technologies Inc. - a wholly owned subsidiary
of Kobe Steel since 1983 - has been the market leader in
direct reduction of iron for nearly 45 years. This success
is based on a simple and efficient process, years of
continuous innovations and improvements, the excellence
of plant operators, and the support from Kobe Steel.
With the emphasis on reducing greenhouse gas emissions
following the ratification of the Paris Agreement, direct
reduction is the only commercially-proven process that
can achieve significant reduction in CO2 emissions for
the iron and steel industry today, using natural gas or
liquified natural gas (LNG). The MIDREX H2™ is an
evolution of the MIDREX® Process that can produce iron
with almost no CO2 emissions; but it requires amounts of
hydrogen that are not currently available from renewable
sources today. This article describes the MIDREX® Process and significant improvements made over the
last 50 years and offers a vision of ultra-low carbon
ironmaking that can be realized in the hydrogen economy.
|
|
| 41 |
Destruction of Old or Abandoned Chemical Weapons by Controlled Detonation
|
|
|
|
Ryusuke KITAMURA
|
|
|
While a large part of the world's stockpile of chemical
weapons has been destroyed already, the destruction
of non-stockpiled chemical weapons will continue in
the future. Dismantling non-stockpiled chemical
munitions such as old/abandoned chemical weapons is a
very difficult task and involves a high risk of accidents.
Controlled detonation is suitable for old/abandoned
chemical weapons, since it can destroy chemical
munitions without prior dismantling. In controlled
detonation, the shells of chemical munitions are
fragmented, and the chemical agents and explosives filling
the shells are destroyed by the shock wave, as well as
by the high-pressure and high-temperature environment
produced by the detonation of the donor charge. A
detonation chamber and a controlled detonation system,
whose main component is the detonation chamber,
have been developed and used in destroying many old/abandoned chemical weapons in and out of Japan since
2004. The controlled detonation system and destruction of
chemical weapons are outlined in this report.
|
|
| 47 |
Design of Detonation Chamber for Destructing Chemical Warfare Materials
|
|
|
|
Koichi HAYASHI
|
|
|
A detonation chamber is a device for destroying chemical
warfare materials by detonation, using tens of kilograms
of explosives in the process. Special structural features
are required to satisfy fragment resistance, operability
and leak tightness. The normal design code for static
pressure vessels cannot be applied to the basic structural
design of the robust detonation chamber because the
detonation shock wave causes instantaneous dynamic
pressure. Hence, the Code Case "Impulsively loaded
pressure vessels," published recently by the American
Society of Mechanical Engineers (ASME), was used as the
design guideline. It requires dynamic pressure analysis
and dynamic stress and strain analysis, which are used
for the evaluation of each mode of failure such as fatigue
damage and local strain limit, to allow detailed design.
This paper introduces the design features with examples.
|
|
|
<Feature-Ⅱ> Advanced Materials Business
|
|
|
| 54 |
Strengthening of Aluminum Alloy Forgings for Automotive Suspension by Two-step
Aging
|
|
|
|
Masayuki HORI, Kenichi HIRUKAWA, Masashi NAKANO,
Masakazu TANAKA, Yohei OKAFUJI
|
|
|
In order to improve the fuel efficiency of automobiles,
it is important to reduce the weight of vehicle bodies.
The weight of suspensions is also being reduced, by
applying Al-Mg-Si aluminum alloy forgings, for example.
Further reducing the weight of suspensions will require
additional strengthening of the material, and Kobe Steel
has conducted a study to increase the strength by two-step
aging. As a result, a two-step aging process combining
pre-aging at 160℃ and high-temperature aging at 190℃
has achieved a peak proof stress of 390 MPa in a short
time period of only 8 hours. Obtaining the same peak
proof stress by single-step aging at 160℃ requires 56
hours. This is attributed to the fact that β″ phase, having
a size of 3 to 4 nm, which is greater than the critical size
for non-reversion, precipitates with a high number density
during the pre-aging and grows at the high temperature
to increase the strength. This technology has enabled a
weight reduction of 3% over that of the conventional
technology and is expected to contribute to improving fuel
efficiency and reducing the carbon dioxide emissions of
automobiles.
|
|
| 59 |
Mechanism of Attaining High Strength Sintered and Surface-rolled Gear and Merits
of Its Application in Automotive Field
|
|
|
|
Yuji TANIGUCHI, Satoshi NISHIDA
|
|
|
With the aim of expanding the application to automobiles,
a study was conducted to determine the applicability
of sintered parts to transmission gears that require
high fatigue strength. Recent studies have reported that
sintered and surface-rolled gears based on pre-alloyed
steel powder can achieve fatigue strength equal to or
higher than that of conventional wrought steel gears,
but the mechanism that enables the former to achieve
a fatigue strength higher than that of the latter has not
been fully clarified. Hence, Kobe Steel has investigated
the factors that may bring higher fatigue strength to
sintered and surface-rolled gears in comparison with
wrought steel and found that it is attributable to their
highly compressive residual stress. Also studied were
the advantages of applying sintered and surface-rolled
gears. By optimizing the surface-rolling conditions so as
to improve the tooth profile accuracy, the same contact-pressure
fatigue strength as that of the ground product
can be obtained without any grinding, suggesting the
possibility of eliminating the grinding process.
|
|
| 65 |
Melting and Casting Technologies for Titanium Aluminide Intermetallics
|
|
|
|
Daisuke MATSUWAKA, Tomohiro NISHIMURA, Fumiaki KUDO,
Yuuzo MORIKAWA, Hitoshi ISHIDA
|
|
|
Alloys based on the titanium aluminide (TiAl)
intermetallic compound are lightweight and have
excellent high temperature strength and oxidation
resistance. Therefore, they are being increasingly used in
low-pressure turbine blades of jet engines for commercial
aircraft, against the backdrop of fuel consumption
reduction needs and the like. Kobe Steel has been working
on the development of a manufacturing technology for
TiAl material with international competitiveness, devised
a melt deoxidation method utilizing the phenomenon of
decreased oxygen solubility when high concentration
aluminum is added, and achieved an oxygen
concentration of 0.03 mass% or less. The company has
also realized a narrow composition range (Al content
±0.3 mass%) and improved casting yield (+25% or higher
compared with the conventional method) by constructing
a melting and casting process using the cold crucible
induction melting (CCIM) method. This paper also details
the technology for recycling titanium scrap and describes
future prospects.
|
|
| 70 |
Evaluation for Morphology of Regions Having Microtexture in Ti-6Al-4V Alloy
Forging Products
|
|
|
|
Dr. Yoshinori ITO, Dr. Hiroyuki TAKAMATSU, Shogo SAEKI,
Dr. Nobuhiro TSUJI
|
|
|
Titanium alloys contain regions having microtexture,
in which the crystallographic orientation of the alpha
phase is similar. Because the regions with microtexture
deteriorate mechanical properties, it is important to
evaluate their morphology. In this study, ultrasonic
measurement was conducted, and the results were
compared with characterization results obtained
by the SEM/EBSD method. It has been verified that
backscattered signals by ultrasonic measurement can be
used for the evaluation of the regions having microtexture.
|
|
| 76 |
An Approach to Increase Strength of Materials for Built-up Type Crankshafts
|
|
|
|
Tsukasa SHIRAFUJI, Hiroyuki TAKAOKA, Ryota YAKURA
|
|
|
Recently, there is an increasing need for improving
the efficiency of low-speed diesel engines for ships. In
response, Kobe Steel has newly developed an inexpensive
low-alloyed steel for semi-built-up type crankshafts. This
steel has a high yield point and high fatigue strength
while avoiding the risk of quench cracking, which often
occurs in large, forged steel products. Crank throws
were manufactured from multiple steel types, including
the newly developed steel, and the material properties of
samples of steel pieces taken from their major parts were
evaluated. The results confirmed that the newly developed
steel has mechanical properties and a fatigue strength
superior to those of conventional steel. It is expected
that this newly developed steel will be applied to next-generation
engines and contribute to compliance with
environmental regulations, which are expected to become
increasingly stringent.
|
|
| 82 |
Automatic X-ray Stress Measurement System for Cold-rolled Fillet of Solid-type
Crankshafts
|
|
|
|
Dr. Mariko MATSUDA, Hitomi ADACHI, Tatsuhiko KABUTOMORI,
Dr. Hiroyuki TAKAMATSU, Dr. Toshihiko SASAKI
|
|
|
In recent years, attention has been being paid to global
environmental problems, and even higher fatigue strength
is required for crankshafts used in medium-speed diesel
engines for onshore power generation. Surface treatment
technology is drawing attention as one of the means to
achieve this. In any of the surface treatment technologies,
however, a tensile residual stress, which causes a
decrease in fatigue strength, occurs at the boundary
between the surface treated part and the untreated part,
and it is necessary to understand the residual stress
distribution around the surface treated part. This paper
describes the evaluation of the influence of the macro-segregation
peculiar to large, forged steel, and the
X-ray incident angle and incident angle setting error,
generated during fillet measurement, on the accuracy
of X-ray stress measurement by the cos α method.
Improvement measures are also described. In addition,
the effectiveness of a system that can automatically and
high-speed measure the residual stress in the cold rolled
fillet has been demonstrated.
|
|
|
|
 |
|
 |
|
