Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
11~6361
Heat Recovery from ~n Internal Combustion Enginefor SupplementQr~ Power,
It i9 known that approximately(one~th~rd of the fuel
energy in an lnternal combustion engine i8 given o~f Q~ heat
in the exhaust gases; and a similar amount of heat i~ carr-
ied away by the engine coolant. This invention relates to
the reco~ary of heat from both the exhaust gases and englne
coolant o~ any internal combustion engine, includlng diesel
engines,to pro~ide supplementary power, such as by heating
a n uid to drive a steam or vapour turbine. ~here i8 a hig~
temperature stage o~ heat recovery ~nd a lower temperatvre
stage. Heat from the lower tempeI~ture Btage i9 elevated in
temperature by a heat pump cycle and then delivered to the
high temperature stage.
Related patents on thi3 sub~e¢t may be described a~
follows s -
Combined gas turbine, ~team turbine sy~tem~ ~avebe~n propo~ed in Unite~ Sta~es Patent to Miller, No.
2, 678, 531 and No. 2,678,532 of May 16, 1954, wherein steam
is combined with combu~tion gases in the 9am9 combu~tion
chamber, to cool the combu~tion gases prior to their lntro-
duction 1nto the tur~ine.
There i~ a United State~ Patent 3,385,565 to Aguet
of August 15, 1967 wherein a combustion chamber ~or pressur-
ized gas and air includes a superheater whose steam drivas
a ~eparate steam turbine; the combustion gases drlving a
separate turbine; and the exhaust ga9 from the ga~ turbine
preheats the liquid. The steam enters the combustion chamber
at two locations, both fed ~rom the expanded steam exiting from
the steam turbine.
A C~adian Patent No. 998,843 i88ued 76 - 10 - 26
to M~gneault, de~¢ribes a comb~ned gQs and steQm motor
compri~ing two engine~ operatively connected to Jointly
drlve a power ~haft; a combustion chamber ln 3aid motor hav-
ing ignition means therein and a boiler mean~ therein. Thu~
the boiler i8 contained within the combustion chamber and
combu~tion is attained by the lgnition of pre~surlzed fuel
and pre~surized air, both supplied by pre~ure tanks and
pump8~ A sultable liquid such as water is conducted ~hrough
~a¢ket~ around the combustion chamber and through a condenser
having a baffled tank, pump, shower and supplementary burner
for pre~entlng freeze-up. ~he ¢ombu~tion gas jet n ame is
directed into the pre~ure chamber of a motor to drtve ~ame,
while ~team builds up, whereupon the ~taam is also directed
tnto the pre~sure chamber. The mixln~ of the flulds occurs
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in the pre~ure cham~er, not. ~n the combustion chamher.
In one embodiment thensteam ~nd combu~tion ga~es are conducted
lnto the cylinders of a pi~ton-type engine at a pressure of
abou~ 800 p.5.i. Other embodiment~ include a combined g~8
and ~team motor compri~ing two turbine~; or a ~in~Jle turblne
hou~lng and a rotor ha~ng ~tenm turbine vane~ on one side
and g~ ~et vane~ on the other. In both case~ the combu~t-
ion chamber ha~ a boiler means therein to produce ~team to
supplement the ga~ fuel. An additional embodiment i~ a rel-
atively ~mall combined ~team condenserl ga8 and steam engine
~aid engine having a combustion chamber, a boiler therein,
and an engin~ housing containing at least one pressure cham-
ber with a mo~eable part driv~ngly connected to a power sha~t.
~hs ~pent 6te~m ie condensed and recycled ~o the boiler.
Canadian Patent No. 986,727 i~ued to ~ggmann in 76 -
04 - 06 de~cribes a hybrid motor unit with energy ~torage.
In substance it i9 a method of operating an lntarnal ¢om-
bust,ion engine arranged to drive a load, n~hereln a small
portion of the engine power dri~e~ an air ¢ompra~sor~ the
pre~suri~ed air iflnstored to meet acceleration requirement~
of the load by ~upplying ~aid ~tored air through a he~t
ex¢hanger, which i~ heated by exhaust gase~ *rom the engine
to an air- operated turbine in driving oonnection with the
load. It clalms to provide extra power only for a¢celeration.
In Canadian Patent No. 449, 146 is~ued to Barr, June
15, 1948 i9 described an internal combu~tion compounde~
turbine, an inoluded steam turbine and a heat interchang~r
which~extracts heat from the exhaust gases o~ the lowest
pressure internal combustion turbine of the oompounded
serie~ for rai~in~ ~tea~ wh~ch is u~ed to drive the steam
turbine. The water ~upply of the heat interchanger i8 UBed
to cool the compressor/s or intercooler/s, the feed water
being thereby pre-heated. The ~team turbine provides ~upp-
lementary power w~ t its exhau~t ~team may be condensed
and returned to the feed water supply.
~ he inventlon herein differs from known inventions
in the following wayst
(a) It i~ adaptible to any internal combustion eng-
ine, in¢luding die~el engines, and $ncluding existing
engines, without significant modification to those engines.
(b) It reco~ers heat from three ~ource~s (i) e~hau~t
ga~es; (ii) engine coolant and ~ili) eXhaust steam from
a supplementary turb~ne.
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1146361
(c) It uses a heat pump cycle to raise the temprr-
ature of heat sources which are at alower temperature.
(d) It uses fluid for the supplementary turbine in an
independent circuit, permitting the choice of fluid for
optimum functional characteris$ics.
(e) The steam or vapour turbine, utilizing the recover-
ed heat, can supply power continuously, and not ~ust for
for acceleration or other spadmodic loads.
Specification
The drawings which lllustrate the embodiments of
the invention are:
Figure 1, A schematic diagram of the heat recovery
system.
Figure 2, The assembly of the heat recovery system
and driven turbine, top view.
Figure 3, The assembly of the heat recovery system
and driven turbine, ~ide view.
The heat recovery system comprises four flow
circuits which are described as follows:
With reference to Figure 1, (solid line), exhaust
gases from the internal combustion engine,l, enter a heat
exchanger,2, within a steam-generating boiler,3, Upon exit-
ing from said heat exchanger the exhaust gases pass through
a second heat exchanger,4, within an evaporator, 5, and
exit at 6 to the atmosphere, directly or through a silencer.
The second flow circuit (dashed line) conducts the
circulating engine coolant of the internal combustion eng-
ine,l, into a heat exchanger,7, within ~irst stage evap-
orator, ~ 27, from which it retu~ns to the internal com-
bustion engine,l.
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The third flow circuit ( dash-dot line) comprises a
heat pump cycle. The heat pump fluid is compressed by
compressor, 8; enters heat exchanger, 9, within boiler,
3, and then passes through ~xpansion valve, 10, or alter-
native expansion turbine, 11. After expansion the heat
pump fluid enters first stage evaporator, 27, From said
evaporator the heat pump fluid, in a vapour state, flows
into second stage evaporator, 5, via conduit 28; and from
said evaporator the said fluid returns to ~ompressor, 8,
via conduit 19.
The fourth flow circuit ( dash, two-dot line)
conducts steam or vapour from boiler, 3, to drive a
turbine, 12, or other form of engine via conduit, 2~.
The exhaust fluid from said turbine is conducted through
heat exchanger, 13, ~Nithin first stage evaporator, 27;
and the condensate is returned to the boiler, 3, by
pump 14, via conduit, 29. See Figs. 2 ~ 3 for operation:
In operation, exhaust gases from internal combust-
ion engine, 1, flow through heat exchanger, 2, in boiler,
~,~provi~ing5direct heat to produce steam or vapour in
said boiler. Upon exiting from heat exchanger, 2, the
said exhaust gases, at reduced temperature, pass through
a second heat exchanger, 4, in second stage evaporator
5, In said evaporator additional heat is extracted from
said exhaust gases by the heat pump vapour therein. The
heat pump fluid extracts heat from two other sources,
namely: the coolant of the internal combustion engine,
and the exhaust fluid from the supplementary turbine, 12~
when it is operating. The said engine coolant enters heat
exchanger, 7, in first stage evaporator, 27, via conduit
22. Said coolant returns to said engine via conduit, 23.
The exhaust fluid from the supplementary turbine, 12,
enters heat exchanger, 13, in first stage evaporator, 27,
via conduit, 21. The condensate of said fluid is returned
to boiler. 3, by pump, 14. The heat pump fluid, after
passing through expansion valve, 10, extracts heat in
the said first and second evaporator stages. The heat
~1~6361
~ump fluid i~ then dra~r~ into compressor, 8, via conduit,
vi~ cQ~auit 17,
19, where its temperature is raised; and it is e~reLle~
into heat exchanger, 9, in boiler, 3. ~he heat pum~
is the indirect mode of providing high temperature heat
to boiler, 3. '~he steam or vapour produced in boiler, 3,
by heat exchanger~, 2 and 9, drives supplementary turbine,
or other engine, 12, via conduit, 20 and throttle, 24.
The characteristics or properties of the turbine
fluid, the heat pump fluid and the engine coolant may be
chosen for an optimum temperature range in the evaporator
stages. The engine coolant, for example, if circulated
under pressure, and/or contains ethylene glycol (anti-
freeze) will have a higher boiling temperature than
water alone. ~he heat pump fluid will be chosen to have
an evaporating temperature below the boiling temperature
of water, for example; an-d at a practical compressor
pressure will have a temperature sufficiently high to
add heat to the boiler, 3. The heat exchangers, 4, 7,
and 13, in the evaporator stages will be designed for
a low pressure drop and optimum heat transfer according
to a known art.
~ he supplementary turbine, 12, may be coupled to
the internal combustion engine, 1, by an automatic clutch,
of known art, or bx x~px may be independent; and will
have means of control and safety in accordance with known
practice.
In very large internal combustion installations
an expansion ~ turbine, 11, may be substiuted ~or expans-
ion valve, 10. Said expansion turbine may be used as an
auxiliary power source.
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