POWER October 2014 - 54

COMBUSTION TURBINES
Quickly Boost Your Combustion
Turbine Response
Morris Cogeneration, a combined cycle cogeneration plant near Chicago, has
installed TurboPHASE, a fast-responding, modular " turbocharger " installed
to boost capacity and PJM regulation revenue. How does it perform?
Dr. Robert Peltier, PE
T
wice this year, PJM flirted with blackouts
when brutal winter storms (dubbed
a polar vortex) struck the Eastern U.S.
in January. The cold weather set a new winter
peak demand record of 141,500 MW on Jan.
7, busting the record set in February 2007
by nearly 5,000 MW. In fact, the five biggest
demands ever placed on the PJM grid,
and eight of the 10 largest, occurred between
Jan. 7 and Jan. 30. PJM reported that at one
point, 36,000 MW was out of service due to
forced outages, which amounts to 20% of its
installed capacity. Adam Keech, director of
wholesale market operations, is reported by
RTO Insider as saying-the morning after
setting the winter peak record- " We really
exhausted every megawatt we had on the system. "
Peaking capacity and fast unit response
is a necessity during summer and winter
peaks, and many regional transmission organizations
(RTOs) are willing to pay well for
the service.
A solid majority of new plant construction
in PJM is gas fired, led by simple or combined
cycle plants. Simple cycle combustion
turbine (CT) plants are less efficient than
combined cycle plants but are able to start
more rapidly and add valuable power to the
grid in minutes, which is extremely valuable
to a system like PJM as synchronized reserve,
fast grid regulation, or black start service. In
fact, ancillary service payments often justify
the cost of constructing a simple cycle peaking
plant.
A New Option
Jupiter, Florida-based PowerPhase LLC has
successfully demonstrated a new technology
called TurboPHASE that may allow an existing
simple cycle CT or combined cycle plant
to add as much as 10% to 20% more power
to the grid in seconds, depending on plant
configuration, addressing the quick-start and
fast-response needs of the modern grid.
The TurboPHASE system consists of a
multistage intercooled centrifugal compressor
that delivers hot compressed air to the CT's
compressor discharge section, thereby allow54
ing
the CT to operate at its rated capacity irrespective
of the ambient conditions (5C to
50C) or altitude (Figure 1). The system takes
advantage of the CT operating below its limits
during hot weather much like an inlet chiller
or evaporative cooling system, although TurboPHASE
can also operate in conjunction
with either of those inlet cooling options.
A separately fueled reciprocating engine
direct drives the compressor. The heat from
the exhaust of the engine is used to heat the
compressed air in the recuperator before entering
the CT compressor section. On an operating
CT, TurboPHASE is said to be able
to ramp to full load in 60 seconds or less and
from part load to full load in 10 seconds or
less. This design feature is sure to be of interest
to grid dispatchers anxious to have the
ability to quickly backfill lost capacity during
a system emergency or to quickly respond to
the intermittency of renewable resources.
Field Tests Completed
Two prototype TurboPHASE modules
(TPMs) were tested in August, and the data
and test results were provided to POWER on
an exclusive basis. The tests were conducted
at Atlantic Power Corp.'s Morris Cogeneration
Plant (Morris), located just outside
Chicago (Figure 2). The gas-fired 177-MW
combined cycle facility is located within the
Equistar Chemicals petrochemical plant in
Morris, Ill. All of the steam (after passing
through a steam turbine) and a portion of
the electricity produced by the plant is sold
to Equistar, and the remainder of the power
is sold into the PJM West market. Morris is
configured with three gas-fired General Electric
Frame 6B CTs, each with a heat-recovery
steam generator (HRSG).
PowerPhase engineers ran a series of predictive
performance models using ThermoFlow
in advance of the field tests. The models
predicted that the CT full-load performance
would increase ~2.63 MW and the steam turbine
by ~0.43 MW, for a total power increase
of ~3.06 MW. The cost of the increased output
is the additional fuel burned by the CT
(~10 MMBtu/hr) and the fuel burned by the
engine (~16.3 MMBtu/hr). Therefore, the incremental
heat rate of the unit with one TPM
in service was expected to be on the order of
26.3 MMBtu/hr/3.06 MW = 8,650 Btu/kWh.
The demonstration test was conducted
in two parts. The first test was designed to
demonstrate the increase in output capacity
1. Turbocharging combustion turbines. TurboPHASE consists of four main components:
engine, gearbox, compressor, and recuperator. A gas-fired engine-c ompressor set
produces compressed air that is added to the combustion turbine's compressor discharge
section to negate the effect of a high ambient temperature performance derate. Courtesy:
PowerPhase LLC
Air vent silencer
Muffler
Compressor
inlet air filter
Recuperator
CO catalyst
Engine exhaust
Gearbox
6 " air injection valve
3 " air vent valve
Compressor and
intercoolers
Coupling
Lube oil system
and cooler
www.powermag.com
Engine
Engine
cooler
POWER | October 2014
http://www.powermag.com
POWER October 2014

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