A low compression turbocharged diesel engine is provided in which the turbocharger can be operated independently of the engine to power auxiliary equipment. Fuel and air are burned in a catalytic combustor to drive the turbine wheel of turbine section which is initially caused to rotate by starter motor. By opening a flapper value, compressed air from the blower section is directed to catalytic combustor when it is heated and expanded, serving to drive the turbine wheel and also to heat the catalytic element. To start, engine valve is closed, combustion is terminated in catalytic combustor, and the valve is then opened to utilize air from the blower for the air driven motor. When the engine starts, the constituents in its exhaust gas react in the catalytic element and the heat generated provides additional energy for the turbine section

Ream, L. W.

English

NASA Technical Reports Server

United States Patent [191 [111 4,449,370 
Ream [45] May 22, 1984 
[54] DIESEL ENGINE CATALYTIC COMBUSTOR 
[75] Inventor: Lloyd W. Ream, N. Canton, Ohio 
[73] Assignee: The United States of America as 
SYSTEM 
represented by the Administrator of 
the National Aeronautics and Space 
Administration, Washington, D.C. 
[21] Appl. No.: 157,150 
[22] Filed: Jun. 6,1980 
[51] Int. Cl.3 ......................... FO2B 37/00; FOlN 3/36 
[52] U.S. Cl. ......................................... 60/606; 60/303 
[58] Field of Search .......................... 60/606, 280, 303 
[561 References Cited 
U.S. PATENT DOCUMENTS 
2,216,494 10/1940 Kurtz et al. ........................... 60/606 
2,585,029 2/1952 Nettel .................................... 60/606 
2,669,090 2/1954 Jackson ............................. 60/606 X 
2,921,431 1/1960 Sampietro ............................. 60/606 
3,048,005 8/1962 Egli et al. ......................... 60/606 X 
3,676,999 7/1972 Oldfield ................................ 60/606 
3,775,971 12/1973 Gadefelt ........................... 60/606 X 
4,018,053 4/1977 Rudert et al. ......................... 60/606 
4,054,418 10/1977 Miller et al. ...................... 60/303 X 
4,122,673 10/1978 Leins ................................. 60/280 X 
4,215,549 8/1980 Daeschner ............................ 60/606 
FOREIGN PATENT DOCUMENTS 
588160 12/1959 Canada .................................. 60/606 
537483 6/1941 United Kingdom .................. 60/606 
Primary Examiner-Michael Koczo 
Attorney, Agent, or Firm-N. Musial; J. Manning; J. 
Mackin 
~571 ABSTRACT 
The object of the invention is to provide a low compres- 
sion turbocharged diesel engine in which the turbo- 
charger can be operated independently of the engine to 
power auxiliary equipment. As shown in FIG. 1, fuel 
and air are burned in a catalytic combustor 17 to drive 
the turbine wheel of turbine section 110 which is ini- 
tially caused to rotate by starter motor 9. By opening 
flapper valve 26, compressed air from blower section 
116 is directed to catalytic combustor 17 when it is 
heated and expanded, serving to drive the turbine wheel 
and also to heat the catalytic element 32 shown in FIG. 
2. To start engine 10, valve 26 is closed, combustion is 
terminated in catalytic combustor 17, and valve 20 is 
then opened to utilize air from bl'ower llb for air driven 
motor 21. When engine 10 starts, the constituents in its 
exhaust gas react in the catalytic element 32 and the 
heat generated provides additional energy for the tur- 
bine section lla. 
3 Claims, 2 Drawing Figures 
& I la 
https://ntrs.nasa.gov/search.jsp?R=19840025737 2020-03-22T10:22:52+00:00Z
U.S. Patent May 22, 1984 Sheet 1 of 2 4,449,370 
L 
U S  Patent May 22, 1984 Sheet 2 of 2 4,449,3 70 
1 
4,449,370 
2 
posed in the exhaust system between the engine and the 
turbine of a turbocharger. Fuel may be injected into the 
after-burner to increase the energy of the turbine wheel. 
Valves are provided to supply additional amounts of air 
5 to the after-burner and to recirculate some of the ex- 
haust gas to the intake system of the engine. 
Neither of the above-identified patents involves any 
use of a catalytic combustion with a turbocharger to 
drive auxiliary equipment when an aircraft is parked on 
both patents involve problems of flame-out and restart- 
ing with regard to the after-burner and auxiliary com- 
DISCLOSURE OF INVENTION This invention relates to turbocharged internal com- 15 
bustion engines and is directed more particularly to a 
turbocharged diesel engine for aircraft use. In accordance with the invention turbocharged, 
Because of the urgent need to reduce the amount of lightweight diesel engine is provilded with a starter/al- 
crude oil imported to the United States, a high priority ternator and an oil pump mechanically driven from a 
has been placed on increasing the fuel economy of vari- shaft through which the turbine wheel of a turbo- 
ous internal combustion engines including those used in 2o charger drives the turbocharger blower and has a cata- 
light aircraft. It is well-known that the brake specific lytic combustor disposed in the exhaust system between 
fuel consumption for diesel engines is much lower than the engine and the turbine wheel. A by-pass conduit 
for spark ignition type 'gasoline engines. extends from the exhaust system at' a point upstream of 
For aircraft use, diesel engines are considered to be the catalytic combustor to an intake conduit extending 
safer than spark ignition engines because no electrical 25 between the blower of the turbocharger and the intake 
ignition system is used and, consequantly there are no of the engine and is provided with a flapper valve 
misfires. Further, a diesel can be turbocharged to oper- which can be positioned either to block the by-pass 
ate as effciently at a 24,000 ft. altitude as it would at conduit and open the intake conduit or vice-versa, 
ground level, an advantage which cannot be achieved By positioning the by-pass conduit valve to open the 
either by turbine engines or by supercharged gasoline 30 by-pass conduit but block the intake conduit and by 
engines which are generally limited to about three burning fuel in the catalytic combustor to heat the cata- 
Pounds Per square inch supercharging Pressure. Where lytic element, energy is supplied to the turbine wheel, 
a turbocharger is used, hot air can be bled though a thereby rotating the blower and driving the alternator diesel engine to prevent cooldown as would occur in a 35 and the oil pump. ~i~ from fie blower wheel is diverted 
descent mode. through the by-pass conduit to the exhaust system and 
far as used in aircraft is its great weight which results wheel to the atmosphere. 
tios of 20 to 1 or more. However, by reducing the corn- 4oo" F. or g;eater, the fuel input to the combustor may 
engine can be made very light. With such a low com- the combustor will provide automatic restart without pression ratio, a turbocharger may be used to raise the 
auto-ignition in the diesel engine. However, for starting 45 tion of the engine there is sufficient oxygen in the ex- 
turbocharger before the engine is running. 
An important aspect of light aircraft usage is the 
availability of electrical power from the aircraft itself 
DIESEL ENGINE CATALYTIC COMBUSTOR 
SYSTEM 
DESCRIPTION 
Origin of the Invention 
The invention described herein was made by employ- 
ees of the United States Government and may be manu- 
factured and used by or for the Government for govern- 
thereon or therefor. 
mental purposes without the payment of any royalties " the ground with the engine off a d  the arrangements of 
TECHNICAL FIELD bustion chamber. 
the main disadvantage Of a as through the catalytic comb us to^ and to the turbine 
from making the engine structure strong 
withstand the pressures generated by 
to 
ra- After the catalytic element ofthe catalytic combustor achieves an operating temperature of approx~ately 
Pression ratio to about l4 to Or as low as 8 to the be varied as needed and even though reduced to 
intake air temperature to the 850" Fa needed to provide ignition device such as a during Opera- 
haust gas so that '' air need be su&died to the combus- purposes some means must be provided to activate the tor from an external source to support combustion. 
BRIEF DESCRIPTION OF THE DRAWINGS 
~ 
The details of the invention will be described in con- on the ground with the engine off. A turbo- 50 
charger which can be operated without the engine run- 
ning can be used to drive an alternator or generator to 
provide the needed electrical power. The turbocharger 
can also be used to drive an pump for circulating oil 
through the diesel engine before attempting to start it. 55 type used in the 
nection with the accompanying drawings in which 
FIG. is a schematic drawing of a turbocharged 
FIG. 2 iS a schematic Of a Catalytic combustor Of the 
engine embodying the invention* and 
Of 1. 
BACKGROUND ART 
In the prior art U.S. Pat. No. 4,018,053 discloses an 
internal combustion engine with an exhaust turbo- Referring first to FIG. 1, there is shown an intermit- 
charger and having an external auxiliary combustion 60 tent combustion engine 10 having a turbocharger com- 
chamber which provides hot gas to the exhaust system prised of a turbine wheel section Ila, a blower section 
of the engine. The hot gas from the auxiliary combus- l lb,  and a means for connecting the turbine to drive the 
tion chamber is directed toward the turbine wheel blower such as shaft llc. Air taken in at an air intake 12 
thereby increasing its speed so as to provide increased is compressed and raised in temperature by the blower 
starting-supercharged air pressure as well as additional 65 wheel section l l b  and is directed by an intake conduit 
pressure required under acceleration or heavy load. 13 to an intake port 14 of the engine 10. Exhaust gases 
U.S. Pat. No. 3,775,971 discloses a turbocharged from the engine 10 exit at exhaust port 15 and pass 
internal combustion engine having an after-burner dis- through an exhaust conduit 16, a catalytic combustor 
BEST MODE FOR CARRYING OUT TH . 
INVENTION 
3 
4,449,370 
17, the turbine section l l a  and then through an exhaust 
outlet 18 to atmosphere. 
The temperature of the intake air may be kept within 
a desired range by a intercooler 19 disposed in the in- 
take conduit. Also, compressed air may be tapped off 
from the intake conduit 13 through a valve 20 to a 
,pneumatic starter motor 21 to provide cranking power 
for engine 10. Further, by running the turbocharger 
while engine 10 is inoperative, accessory equipment 
such as an oil pump 22 and a generator 23 may be driven 
from the shaft l l c  by means of various known mechani- 
cal devices as, for example, a gear box 24. With this 
arrangement it is necessary to provide a means such as 
a starter motor 9 to rotate the turbine wheel and blower 
initially. Alternatively, starter 9, gear box 24, oil pump 
22 and generator 23 may be replaced by an alternator- 
oil pump in shaft llc. The alternator serves as a starter 
motor when electrical power is supplied thereto. 
To the end that turbine section l l a  will drive accesso- 
ries 22 and 23 and the blower l l b  while engine 10 is 
inoperative, a bypass conduit 25 is connected from the 
exhaust conduit 16 upstream of catalytic combustor 17 
to the intake conduit 13. In order to block the intake 
conduit 13 and direct air from the blower l l b  through 
the bypass conduit 25 to the combustor when the tur- 
bocharger is to be operated while engine 10 is inactive, 
a flapper valve 26 is positioned at the juncture of by- 
pass conduit 25 and intake conduit 13. 
When engine 10 is inoperative, hot gas is supplied 
from the catalytic combustor 17 to the turbine section 
l l a  by burning fuel in the combustor 17. This fuel is 
supplied from a fuel source 27 through a valve 28. Air 
to support the combustion is supplied from an air source 
29 through a valve 30 to the catalytic combustor 17. 
Referring now to FIG. 2 there is showh in schematic 
detail a catalytic combustor in accordance with the 
invention. Catalytic combustor 17 comprises a housing 
31 closed at one end and having a catalytic element 32 
disposed in an open end, the open end being connected 
through exhaust conduit 16 to the turbocharger turbine 
section lla. The catalytic element 32 may be of palla- 
dium or other noble metals capable of reacting the con- 
stituents of exhaust gas from an internal combustion 
engine. Apertures or slots 33 are provided in the hous- 
ing 31 and are enclosed within an annular manifold 34 
which receives exhaust gas from exhaust conduit 16 or 
air from by-pass conduit 25. 
Between the apertures 33 and the closed end of hous- 
ing 31 there is disposed a combustion chamber 35 into 
which fuel is injected by a fuel nozzle 36. Air is supplied 
to combustion chamber 33 from valve 30. The fuel 
spray from injector 36 is ignited in combustion chamber 
35 by a spark gap 56 energized from an igniter power 
' source 37 to produce a flame 38. A flameholder 39 is 
disposed coaxially with the combustion chamber 35 to 
inhibit flameout conditions and to distribute the hot gas 
generated by the flame uniformly to the catalytic ele- 
ment 32. 
Operation of the engine 10 and turbocharger system 
of FIG. 1 will now be described. Assuming that engine 
10 is inoperative, the turbocharger section l l a  may be 
energized activating starter motor 9 and by providing 
fuel and air to the catalytic combustor 17 to produce hot 
gas. Rotation of the turbine wheel of turbine section l l a  
drives not only the blower wheel of blower section 116 
but also the oil pump 22 and the generator 23. 
With flapper valve 26 positioned to block intake con- 
duit 13, compressed air from the blower 116 is directed 
4 
through by-pass conduit 25 to the catalytic combustor 
17 where it is further raised in temperature and heats the 
catalytic element 32 before passing through turbine 
wheel section l l a  and out through exhaust outlet 18. 
5 After the catalytic element 32 is brought up to about 
400" F., the fuel and air to the catalytic combustor 17 
are adjusted by means of valves 28 and 30 to provide the 
desired thermal output from the combustor. 
After catalytic element 32 is up to the desired temper- 
10 ature, flapper valve 26 is positioned to close the by-pass 
conduit 25 and open intake conduit 13. Compressed air 
from the blower section l l b  may be bled off from intake 
conduit 13 to a pneumatic motor 21 by opening valve 
20. The compressed air to motor 21 causes it to crank 
After engine 10 starts, valve 30 may be closed, shut- 
ting off air to the catalytic combustor 17 since the ex- 
haust gas normally contains sufficient oxygen to sup- 
port combustion in the catalytic combustor. Eventually 
20 valve 28 may also be closed because the catalytic ele- 
ment 32 adds additional heat to the exhaust gas and, 
consequently, provides additional power to drive the 
turbine wheel of turbine section llu 
Whenever needed, fuel and air can again be provided 
25 to the catalytic combustor to provide additional heating 
of the exhaust gas. To avoid manual control of valves 28 
and 30, a control module 40 may be provided as shown 
in FIG. 1. Input signals are directed to control module 
ure sensor 41 in catalytic combustor 
30 17 and from an engine running sensor 42 on engine 10 
via leads 43 and 44, respectively. Sensor 42 may be, for 
example, a switch which energizes module 40 from a 
battery or it may take the form of a generator which 
provides electrical power to module 40 when engine 10 
35 is operating. Control signals are supplied from control 
module 40 to valves 28 and 30 via leads 45 and 46, 
espectively. The temperature sensor 41 signal causes 
control module 40 to gradually close valves 28 and 30 as 
the catalytic element 32 (FIG. 2) approaches its normal 
40 operating temperature. When engine 10 is started, sen- 
sor 42 signals control module 40, whereby if the cata- 
lytic element of catalytic converter 17 is up to its nor- 
mal temperature, both valves 28 and 30 will close. The 
catalytic element is kept hot by the reactive constituents 
It will be understood that those skilled in the art to 
which the invention pertains may make various changes 
and modifications to the above described invention 
without departing from the spirit and scope thereof as 
15 the engine 10 until the latter starts. 
45 in the exhaust gas from engine 10. 
50 set forth in the claims appended hereto. 
I claim: 
1. In combination with an intermittent combustion 
engine of the type having a turbocharger with a turbine 
wheel driven by engine exhaust gases directed thereto 
55 by an exhaust conduit and with a blower which pro- 
vides air under pressure to said engine through an intake 
conduit, said blower being mechanically connected to 
said turbine: 
(1) a catalytic combustor disposed in said exhaust 
an elongated housing having a closed end and an 
open end, said open end communicating with 
said turbine wheel, and further having slots 
which communicate with said engine through 
said exhaust conduit, said slots being disposed in 
said housing in the form of an annular row; 
a catalytic element disposed at the open end of said 
catalytic combustor; 
60 conduit, and comprising: 
65 
4,449,370 
5 6 
a cylindrical combustion chamber disposed be- terminate injection of air into said combustion 
tween the closed end of said elongated housing chamber; 
(4) means for automatically adjusting said first and and said slots which communicate with said second valves when said catalytic element attains a 
engine; 5 predetermined temperature whereby overheating 
means for injecting fuel into said combustion cham- of said catalytic element is prevented; 
ber; (5 )  means coacting with said means for adjusting said 
means for injecting air into said combustion cham- first and second valves to close said first and sec- 
ber; ond valves when said catalytic element is at or 
means for igniting said fuel injected into said corn- 10 above a temperature of 4001" F. and said engine i S  
operating whereby combustor restart is automatic bustion chamber; when said first and second valves reopen; and, a flared apeflured tube disposed Out- (6) an intercooler disposed in said intake conduit to 
wardly of said combustion chamber and extend- reduce the temperature of the air being provided to 
ing toward said slots which communicate with 15 Said engine. 
said engine to inhibit flameout and to uniformly 2. The engine-turbocharger system of claim 1 
heat said catalytic element; wherein said catalytic element is selected from the 
bon emissions from the exhaust conduit by catalyzing a 
20 chemical reaction between the constituents of the ex- 
haust gas. 
3. The engine-turbocharger system of claim 2 
wherein said catalytic element is palladium. 
(2) a fuel supply connected to said means for injecting POUP of noble metals which Will minimize hydrocar- 
fuel through a first which may be closed to 
terminate injection of fuel into said combustion 
chamber; 
(3) an air supply connected to said means for injecting 
air through a second valve which may be closed to * * I * *  
25 
30 
35 
40 
45 
50 
55 
65 


Diesel engine catalytic combustor system

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