U.S. patent application number 10/659334 was filed with the patent office on 2005-03-17 for helicopter turbine engine protection system.
This patent application is currently assigned to SAFE FLIGHT INSTRUMENT CORPORATION. Invention is credited to Greene, Leonard M..
Application Number | 20050056724 10/659334 |
Document ID | / |
Family ID | 33160016 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050056724 |
Kind Code |
A1 |
Greene, Leonard M. |
March 17, 2005 |
Helicopter turbine engine protection system
Abstract
A helicopter having a helicopter turbine engine disposed therein
includes an over-stress protection system. The over-stress
protection system includes a computer for storing data and an input
such as a keyboard for inputting a safe temperature profile for
starting the turbine engine. A temperature sensor is provided for
measuring the actual turbine outlet temperature during the start up
of the helicopter turbine engine. The actual engine temperature is
then compared with the safe engine temperature profile and water
and/or alcohol is injected into the engine when an actual
temperature exceeds the safe temperature. The use of a ground based
tank for use during start up and airborne tank for in flight use
are also disclosed.
Inventors: |
Greene, Leonard M.; (White
Plains, NY) |
Correspondence
Address: |
DENNISON, SCHULTZ, DOUGHERTY & MACDONALD
1727 KING STREET
SUITE 105
ALEXANDRIA
VA
22314
US
|
Assignee: |
SAFE FLIGHT INSTRUMENT
CORPORATION
|
Family ID: |
33160016 |
Appl. No.: |
10/659334 |
Filed: |
September 11, 2003 |
Current U.S.
Class: |
244/10 |
Current CPC
Class: |
F02C 3/305 20130101;
F05D 2220/329 20130101; Y02T 50/675 20130101; F05D 2270/303
20130101; Y02T 50/60 20130101; F05D 2270/112 20130101; B64D 33/08
20130101; F02C 7/143 20130101; B64D 31/06 20130101; F02C 3/30
20130101 |
Class at
Publication: |
244/010 |
International
Class: |
B64C 027/22 |
Claims
1. In a helicopter of the type having a helicopter turbine engine
mounted in the helicopter, the improvement comprising an
over-stress protection system including: data storage means and
means for inputting a safe temperature profile for starting the
helicopter turbine engine; means for measuring the actual
temperature during start up of the helicopter turbine engine;
comparison means for producing a signal when the actual engine
temperature during an engine start up falls outside of the safe
temperature profile; and a source of water and/or alcohol and means
for injecting a predetermined amount of water and/or alcohol into
the turbine engine during the engine start up procedure in response
to said signal.
2. In a helicopter in accordance with claim 1 in which the
helicopter includes a water tank disposed or mounted in said
helicopter.
3. In a helicopter in accordance with claim 1 in which a ground
source of water and/or alcohol provides the water and/or alcohol
for injection into the engine.
4. In a helicopter of the type having a helicopter turbine engine
mounted within the helicopter, the improvement comprising an
airborne tank for containing a supply of water and/or alcohol and
an inlet for receiving a supply of water and/or alcohol from a
ground based source, means for injecting water and/or alcohol into
the helicopter turbine engine during a start up procedure while
maintaining the airborne tank full of water or alcohol, means for
disconnecting the supply of water or alcohol from the ground based
source upon completion of the start up procedure and means for
injecting water and/or alcohol from the airborne tank into the
turbine engine in response to an engine over-stress during flight
operations.
5. (Cancelled)
6. (Cancelled)
7. (Cancelled)
8. (Cancelled)
9. (Cancelled)
10. (Cancelled)
11. A helicopter turbine engine over-stress protection system
comprising: a helicopter; a helicopter turbine engine mounted in
said helicopter; an airborne tank for containing water and/or
alcohol disposed within said helicopter and an inlet for receiving
water and/or alcohol from a ground source of water and/or alcohol;
data storage means and means for inputting a safe temperature
profile for starting the helicopter turbine engine; means for
measuring the actual engine temperature during start up of a
helicopter turbine engine; means for sensing at least one critical
operating parameter during flight operations; comparison means for
producing a signal when the actual engine temperature falls outside
of the safe engine temperature profile during start up of the
engine; means for injecting water and/or alcohol into the
helicopter engine during a start up procedure while maintaining
said airborne tank full of water and/or alcohol; means for
disconnecting the supply of water and/or alcohol from the ground
based source after completion of the start up procedure; and means
for injecting water and/or alcohol from said airborne tank into the
turbine engine in response to an over-stress during flight
operations.
12. A helicopter turbine engine over-stress protection system in
accordance with claim 11 in which said injection means
automatically injects water and/or alcohol into said turbine engine
in response to an engine over-stress during flight operations.
13. A helicopter turbine engine over-stress protection system in
accordance with claim 11 in which said inlet is separate from said
airborne tank.
14. A helicopter turbine engine "hot start" prevention system
comprising: a helicopter; a helicopter turbine engine mounted in
said helicopter; means for selecting a first preselected
temperature and a ten second transient temperature range; means for
detecting a turbine outlet temperature of said engine; a source of
water and/or alcohol for injection into said turbine engine; means
for injecting water and/or alcohol from said source into said
engine when said turbine outlet temperature exceeds said first
preselected temperature; and means to abort said start up procedure
if the turbine outlet temperature fails to fall below the ten
second transient temperature range after injection of water and/or
alcohol.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a helicopter turbine engine
protection system and more particularly to a helicopter having a
turbine engine protection system which injects water and/or alcohol
into the engine when an over-stress condition is approached.
BACKGROUND FOR THE INVENTION
[0002] Helicopter's of the type having turbine engines typically
include turbine outlet temperature monitors to avoid "hot starts."
For example, it is well known that during the first few seconds of
an engine start up procedure, the turbine outlet temperature will
accelerate at a rapid rate. It is also well known to abort a start
if either a maximum temperature, as for example 927.degree. C. or
an 810.degree. C. to 927.degree. C. maximum ten second transition
limitation is about to be exceeded. It is also well known to
operate helicopter engines below predetermined levels of turbine
output temperature, torque and engine speed which are referred to
herein as over-stress limits. Failure to operate within such limits
may seriously damage an engine and/or lead to an engine
failure.
[0003] One approach for starting a gas turbine of the type used for
generating electric power is disclosed in the U.S. Patent of
Takehara et al. U.S. Pat. No. 5,121,596. As disclosed therein, a
gas turbine is started while injecting a prescribed amount of
moisture into a path for combustion gas from the start up of the
gas turbine and the amount of moisture is varied dependent upon the
feed quantity of fuel or the temperature of the combustion gas. In
this way, the combustion temperature in the combustor or
temperature variation rate on the surfaces of component parts in a
gas path are approximately equal.
[0004] An additional U.S. Patent of Moore U.S. Pat. No. 4,619,110
discloses a helicopter engine warning or control system which
includes arrangements for sensing the engine temperature, the
engine speed and the output torque from the engine. An audible
warning is provided which may vary as the over-stress limits are
approached. In addition, an arrangement may be provided for
automatically injecting water or alcohol into the engine as an
over-stress condition is approached.
[0005] It is now believed that there may be a commercial demand and
need for an improved helicopter turbine engine protection system in
accordance with the present invention. There should be a commercial
demand and need for such methods and systems which are used during
start up of a helicopter turbine engine to avoid "hot starts." In
some cases the system will avoid the need to abort the start.
[0006] In addition, the improved systems in accordance with the
present invention are also effective in avoiding an over-stress
situation during flight operations.
BRIEF SUMMARY OF THE INVENTION
[0007] In essence, the present invention contemplates a helicopter
turbine engine "hot start" prevention system. The system includes
means for selecting a first preselected temperature which is below
a critical temperature for the turbine outlet temperature and a ten
second transient temperature range. Means such as a thermocouple
are provided for detecting the turbine outlet temperature of the
engine. The system includes a source of coolant such as water
and/or alcohol for injection into the turbine engine as for example
into a path for combustion gas. Means for injecting water and/or
alcohol from the source into the engine when the turbine outlet
temperature exceeds the first preselected temperature and means to
abort the start up if the temperature fails to fall below the ten
second transient temperature range are provided.
[0008] In a preferred embodiment of the invention, the system also
includes means for detecting an over-stress condition during flight
operations and means for injecting water and/or alcohol into the
turbine engine in response to an over-stress condition.
[0009] A further embodiment of the invention contemplates a
helicopter turbine engine over-stress protection system which
includes a helicopter and a helicopter turbine engine mounted in
the helicopter. An airborne tank for containing water and/or
alcohol is also mounted in the helicopter as is an inlet for
receiving water and/or alcohol from a ground source. The system
also includes data storage means and means inputting a safe
temperature profile for starting the turbine engine. Means for
measuring the actual engine temperature profile during a start up
procedure and comparison means for producing a signal when the
actual engine temperature exceeds the safe engine temperature
profile are also provided. The system in accordance with this
embodiment of this invention also includes means for sensing at
least one critical operating parameter such as engine temperature,
output torque and engine speed during flight operations. A key
function in this embodiment resides in means for injecting water
and/or alcohol into a helicopter engine during a start up procedure
while maintaining the airborne tank full of water and/or alcohol.
In addition, the system includes means such as a quick
connect-disconnect coupling for disconnecting the supply of water
from the ground base source after completion of a start up
procedure and means such as a pump for injecting a predetermined
amount of water and/or alcohol from the airborne tank into the
turbine engine in response to an over-stress condition during
flight operations.
[0010] The invention will now be described in connection with the
accompanying drawings wherein like reference numerals have been
used to identify like parts.
DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side elevational view which shows a helicopter
having an over-stress protection system in accordance with the
present invention;
[0012] FIG. 2 is a schematic illustration of a helicopter turbine
engine for use in practicing the present invention;
[0013] FIG. 3 is a block diagram which illustrates a method for
avoiding "hot starts" in accordance with one embodiment of this
invention; and
[0014] FIG. 4 is a block diagram which illustrates a further
embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE
INVENTION
[0015] As illustrated in FIG. 1, a helicopter 20 having a turbine
engine 22 mounted therein includes an over-stress protection
system. In a first embodiment of the invention, the system is used
to avoid "hot starts" i.e., an excessive engine temperature that
could damage the engine during a start up of the engine. As shown
in FIG. 1, the helicopter 20 also includes a tank 24 for containing
a supply of water and/or alcohol.
[0016] The tank 24 is operatively connected to an injector 26 which
is adapted to inject an engine coolant such as water and/or alcohol
into the engine when the engine temperature exceeds a predetermined
value or when the rate of temperature versus time exceeds a
preselected value. The tank 24 is connected to the injector 26 by a
conduit 25. A pump 21 and valve 23 are disposed along the conduit
25 for supplying a preselected amount of coolant from the tank 24
to the injector 26. The amount of coolant may be varied relative to
the fuel flow and other varients.
[0017] In a second embodiment of the invention, a quick disconnect
coupling 27 is provided in the conduit 25 between the tank 24 and
injector 26. Means such as a ground based tank 30 is adapted to
provide a supply of coolant during a start up procedure. In the
alternative, a quick disconnect coupling 29 of conventional design
may be provided in the tank 24. In either case, water and/or
alcohol is provided to the injector 26 during a start up procedure
while maintaining the airborne tank 24 full of coolant.
[0018] A sensor 32 such as a thermocouple is connected to a
computer 34 for measuring the turbine outlet temperature of the
engine. Then when the turbine outlet temperature exceeds a
predetermined value, the computer sends a signal to the pump 21
and/or valve 23 to feed a volume of coolant to the injector 26. The
water and/or alcohol then cools the engine sufficiently to continue
an engine start procedure. In cases where the turbine outlet
temperature is not sufficiently reduced, the start up procedure is
aborted by any suitable means not shown.
[0019] The use of a ground based tank 30 during a start up reduces
the weight of the coolant in the tank 24 and allows a sufficient
quantity of coolant for use during in flight operations when an
unsafe temperature or critical parameters are approached or
exceeded.
[0020] FIG. 2 is a schematic diagram of a turbine engine of the
type typically used for powering helicopters but includes a turbine
outlet temperature sensor 32 and injector 26 for injecting water
and/or alcohol into the gas stream for cooling the engine and/or
increasing power. As illustrated, air is supplied to the helicopter
turbine engine 22 through an inlet duct 40 and is compressed in the
compressor section 41. Fuel is supplied to the combustion chamber
42 which extends peripherally around the engine. The expanded
gasses are supplied to the turbine portion 44 which drives the
compressor 41 and then to power the turbine 45 which drives an
output power shaft 44 to power the helicopter through a suitable
gear train 47. A torque takeoff 48 of conventional design is
provided for measuring actual torque during flight operations. A
tacometer 49 is also provided for indicating engine speed. In
addition, a temperature sensor 52 or thermocouple is provided for
sensing turbine output temperatures.
[0021] FIG. 3 illustrates a method for avoiding "hot starts" in
accordance with one embodiment of the invention. In conventional
practice, the turbine outlet temperature is monitored to avoid a
"hot start" which could seriously damage an engine. For example, a
start up procedure for one specific engine is aborted if either the
927.degree. C. maximum or the 810.degree. C. to 927.degree. C.
maximum ten second transient limitation is about to be exceeded.
Under such circumstances, the pilot depresses the engine idle rel.
button, closes the throttle and continues to motor the starter
until the turbine outlet temperature falls below 810.degree. C.
[0022] In accordance with the present invention, a start 53 is
initiated as provided in an FAA approved procedure. However, at the
inception or more preferably before initiating a start up
procedure, a safe temperature or safe temperature profile is
inputted into a computer in step 54. Inputting a temperature
profile may be used so that immediate action can be taken as soon
as an actual temperature falls outside of the profile. It is also
believed that the use of a temperature profile may be a more
effective parameter which allows remedial action to be implemented
earlier as the actual temperature approaches a dangerous
condition.
[0023] After completing the FAA mandated prestart check list, the
engine is cranked in step 55, fuel rate set in step 56 and ignition
of the fuel in step 57. In step 58, the turbine outlet temperature
is sensed and monitored. Then if the actual temperature does not
exceed the safe temperature or fall outside of the temperature
profile, the turbine engine is started as illustrated in step 60.
However, if the actual temperature exceeds the safe temperature in
step 59 or falls outside of the safe temperature profile, water,
alcohol or a mixture thereof is injected into the engine in step
61. Following the water and/or alcohol injection, the actual
temperature is monitored in step 62 until the turbine outlet
temperature falls below a safe temperature limit as for example
below 810.degree. C. or falls back into the safe temperature
profile. Then in step 63, if the actual temperature is below the
safe temperature i.e., falls within the safe temperature profile,
the starting procedure is completed. However, if in step 63 the
actual temperature fails to fall below the safe temperature or lies
outside the safe temperature profile, the starting procedure is
aborted in step 64. Under such circumstances, the pilot presses the
engine idle rel. button, closes the throttle and continues to crank
the engine until the temperature falls below the safe temperature
limit.
[0024] It is important to recognize that under ordinary conditions
and a normal start, no water or alcohol is injected into the gas
stream during the start up of the engine.
[0025] A further embodiment of the invention will now be described
with reference to FIG. 4. As shown therein, the start up procedure
is essentially the same as shown in FIG. 3. However, as shown in
FIG. 4, a step 541 replaces step 54 and includes the input of other
critical parameters (CP). For example, other parameters may include
torque and/or engine speed. The start up procedure then continues
until a start has been completed. Then if a ground based water tank
was used, it is disconnected and flight operations commenced.
[0026] During flight operations actual turbine output temperature
and other parameters are sensed in steps 68 and monitored in step
70. As long as the actual temperature does not exceed the safe
temperature on the actual parameters do not exceed the critical
parameters in step 72, the system reverts to the monitoring step as
shown in step 70. However, if the safe temperature or critical
parameters are exceeded, water and/or alcohol is injected from the
airborne tank into the engine as indicated in step 74. In step 76,
it is again determined whether or not the safe temperature or
critical parameters are being exceeded. If not, the system recycles
back to step 70 and the actual temperature and actual parameters
are monitored. However, if the actual temperature or actual
parameters are greater then the safe temperature or critical
parameters, corrective action should be immediately taken as
indicated in step 78.
[0027] While the invention has been described in connection with
its preferred embodiments, it should be recognized the changes and
modifications may be made therein without departing from the scope
of the claims.
* * * * *