POWER September 2020 - 29

TOP PLANT
ed 100% of the fulfillment rate. In the
first half of February, the plant " ran
continuously for 292.8 hours and generated
8.39 GWh electricity with the
average achieving rate of 105.25%,
which broke three records of continuous
operation, electricity generation
and achieving rate set in December
2019, " it said.
The plant's achievements in the first
two years of operations are notable
because " it is widely accepted that
tower CSP plants need three to five
years [of a learning phase] to meet
designed power generation due to its
complexity in terms of technology itself,
[a] complicated process, [and]
a highly difficult operation method. "
A typical engineering, procurement,
and construction contract of a tower
CSP project " accepts 70% to 80%
fulfillment rate for the first year after
completion, " it said. " According to the
released operation data, up to now,
no other player has accomplished the
said target. The expeditious improvement
of Delingha 50-MW project is a
remarkable manifestation of leading
technology, equipment, engineering,
operation of Chinese CSP players. "
Supcon said that at the core of the
plant's good performance is technology
it developed to fit the site's conditions.
For example, the molten salt
receiver, which absorbs the solar energy
reflected onto it by the heliostats
and converts it into thermal energy
via heat transfer media, must " sustain
frequent and sharp temperature
fluctuation and corrosive conditions. "
The receiver is an external tubular/cavity
tubular type made of Inconel Alloy
625 / Haynes Alloy 230 with a black
Pyromark 2500 coating (Figure 1). The
heliostats are also " intelligent. " Designed
to be weather resistant, they
feature an automatic calibration system
and are self-diagnosing. Delingha,
notably, also utilizes six unmanned fully
automatic cleaning vehicles, which
can perform in night-cleaning mode,
Supcon said. Cleaning the entire mirror
field takes about seven days, with
the
vehicles
performing
cleaning
functions twice a day. The automated
cleaners alone help slash labor costs
by 1.2 million RMB ($173,000) a year,
it said.
Supcon also developed the plant's
thermal storage and exchange system,
which consists of hot and cold salt
tanks, a heat exchanger, tubes, instruments,
electric tracing, a heat preserver,
and other auxiliary systems. " The
salt tank can store high-temperature
molten salt to exchange [heat] with water
through heat exchanger to produce
superheated steam for high-quality
power generation, " it explained.
A Digital Lookout and Outlook
Supcon said its total investment in the
project was 1.13 billion RMB ($162.6
million), but it isn't done refining it. The
company is now considering integrating
artificial
intelligence
technology
to reduce weather risks-particularly
stemming from cloud coverage-and
further enhance performance. " The
plant can provide stable electricity
during a short cloudy period, but
sudden and unexpected clouds can
impact operation and lead to system
shut-down, " it explained. That imposes
thermal shocks and heat fatigue on
the receiver, raising safety issues and
wearing down component life. A cloud
forecasting system Supcon developed
promises to track and accurately predict
the direction of cloud movements.
POWER POINTS
Winning Attributes
✔ Though it was of one of China's
first concentrated solar power
tower demonstrations, the 50-MW
Delingha project was commissioned
within 20 months.
✔ Major equipment has run steadily
and the plant has shown it can
exceed its fulfillment rate.
✔ The plant uses several innovative
digital tools to facilitate operation
and maintenance, and others are
being developed to help enhance
performance.
The solution could allow operators to
" formulate corresponding operation
strategies to ensure the safety and
stability of the system, " it said.
Notably, Supcon also uses a " digital
twin " -like platform and other digital
tools to simulate and visualize the
plant's entire process, and to keep
track of performance, operation, and
maintenance needs. These, like much
of the plant's technology, were also developed
and refined in-house, it notes.
" Supcon Solar attaches great importance
to technological innovation and
R&D [research and development] investment,
and has built a professional
solar thermal power generation team
of more than 100 people, of which R&D
personnel account for more than 70%, "
it added. The company also operates a
" high-tech " R&D center, which it said
is China's " largest solar thermal technology
and equipment incubation platform
with the most complete functions
and the most complete facilities. "
Supcon's efforts to improve its technology,
including its smart heliostats
and large-scale mirror field cluster
control technology, and high-temperature
molten salt heat storage and exchange
technology have " reached the
international advanced level, " and " participated
in the first international IEC
[International Electrotechnical Commission]
standard for tower solar thermal, "
it said. That's all part of the package of
the company's longstanding mission to
provide technical research and development
to produce high-quality and lowcost
tower-type CSP and associated
1. This image shows installation of the tower's receiver, which is coated with specially formulated
high-temperature black coating to increase absorptivity. Courtesy: Supcon Solar
September 2020 | POWER
www.powermag.com
molten salt storage, it said. ■
-Sonal Patel is a POWER senior
associate editor.
29

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POWER September 2020

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