U.S. patent number 3,797,562 [Application Number 05/137,318] was granted by the patent office on 1974-03-19 for cooling systems of supercharged diesel engines.
This patent grant is currently assigned to Societe Anonyme De Vehicules Industriels Et D'Equipements Mecaniques. Invention is credited to Yves E. Baguelin, Maurice G. Brille.
United States Patent |
3,797,562 |
Brille , et al. |
March 19, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
COOLING SYSTEMS OF SUPERCHARGED DIESEL ENGINES
Abstract
This invention applicable notably to supercharged Diesel engines
consists essentially in utilizing the engine exhaust gas having
already worked in the turbine of the supercharging turbo-compressor
for inducing in a pump the air necessary more particularly for
partially cooling the lubricating oil and the engine supercharging
air.
Inventors: |
Brille; Maurice G. (Suresnes,
FR), Baguelin; Yves E. (Billancourt, FR) |
Assignee: |
Societe Anonyme De Vehicules
Industriels Et D'Equipements Mecaniques (Suresnes (Hauts de
Seine), FR)
|
Family
ID: |
26215710 |
Appl.
No.: |
05/137,318 |
Filed: |
April 26, 1971 |
Current U.S.
Class: |
165/279;
60/605.1; 123/196AB; 165/104.32; 60/599; 60/616; 165/104.31 |
Current CPC
Class: |
F01P
1/02 (20130101); B60K 11/02 (20130101); F02B
29/0406 (20130101); F01M 5/007 (20130101); F01P
3/20 (20130101); F02B 29/0493 (20130101); F01P
7/026 (20130101); F01P 5/08 (20130101); F02B
29/0443 (20130101); Y02T 10/146 (20130101); Y02T
10/12 (20130101); F02B 3/06 (20130101); F01P
2060/02 (20130101); F01P 2060/04 (20130101) |
Current International
Class: |
B60K
11/02 (20060101); F01P 5/02 (20060101); F01P
1/00 (20060101); F02B 29/00 (20060101); F02B
29/04 (20060101); F01P 1/02 (20060101); F01P
7/02 (20060101); F01P 5/08 (20060101); F01P
7/00 (20060101); F01P 3/20 (20060101); F01M
5/00 (20060101); F02B 3/00 (20060101); F02B
3/06 (20060101); B60h 011/00 () |
Field of
Search: |
;165/15,107,140,39
;123/119C |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Sukalo; Charles
Attorney, Agent or Firm: Stevens, Davis, Miller &
Mosher
Claims
What is claimed as new is:
1. An auxiliary system for cooling diesel engines supercharged by
means of a turbo-compressor driven from the engine exhaust gas
which comprises:
a first heat exchanger in the line from the turbo-charger to the
engine to cool the supercharged air;
a second heat exchanger in the engine lubricating oil line to cool
the oil;
common cooling fluid means in series heat exchange relation with
said first and second heat exchangers;
means sensitive to the pressure of the delivery pipe of the
turbo-compressor for controlling the flow rate of the common fluid
in heat exchanger relation between said first and second heat
exchangers;
means sensitive to the temperature of the diesel system for
controlling the flow rate of said common fluid; and
pump means actuated by the turbo-compressor exhaust for inducing
air into the auxiliary system to remove the heat absorbed by the
system from the diesel engine.
2. A system according to claim 1 wherein said cooling fluid means
comprises a liquid which flows in a conduit through a third heat
exchanger;
said pump means induces air across said third heat exchanger to
cool said liquid; and
said temperature sensitive means comprising a thermostat in a
branch of the liquid conduit which is responsive to the temperature
of the cooling fluid.
3. A system according to claim 1 wherein said cooling fluid is air
which is induced through said auxiliary system by said pump;
said temperature means is responsive to the temperature in the
engine lubricating oil line; and
said pressure sensitive flow controlling means and said temperature
sensitive flow controlling means are connected via a common linkage
to a valve shutter which regulates the amount of air which enters
said auxiliary system downstream of said first and second heat
exchanger and before said pump whereby the amount of cooling air in
the upstream portion of said auxiliary circuit is controlled.
4. A system according to claim 1 wherein said pump comprises:
a circular chamber;
an annular nozzle within said chamber surrounding the neck of a
convergent zone through which the cooling air is caused to
circulate;
a circular set of rectifying blades in said annular nozzle; and
means to tangentially supply the exhaust gas from the turbine of
said turbo-compressor to activate said rectifying blades.
Description
The present invention relates to Diesel engines and has specific
reference to improvements in the cooling system of supercharged
Diesel engines.
It is already known to use the exhaust gas of Diesel engines for
cooling these engines either through the medium of a radiator in
the case of a water-cooled engine, or directly in the case of a
direct air-cooled engine.
This procedure proved to be extremely efficient due to the
considerable amount of energy normally available in the engine
exhaust gas. Unfortunately, the noise was unbearable since the
system constituted a free exhaust one. Attempts have been made with
a view to fit silencers of mufflers in the duct conveying the
gas-air mixture issuing from the pump, but on the one hand this
additional device must have very large dimensions and on the other
hand the residual energy decreases considerably and thus
compromises the cooling efficiency.
The present invention consists in utilizing the exhaust gas having
already worked in the turbine of the turbo-supercharger for
inducing through a pump the air required more particularly for
partially cooling the lubricating oil and the engine supercharging
air.
It is known that the exhaust noise, even in the case of a free
exhaust engine, is reduced considerably and eventually becomes
quite tolerable because an appreciable expansion already took place
in the turbine and the pulsation is merged into a single whistling
noise, to such an extent that many supercharged engines are
operated without any muffler. As a counterpart, the residual energy
available in the exhaust gas is strongly reduced and the pump
efficiency would not be sufficient to induce the whole of the air
required for properly cooling the engine.
In view of the foregoing, and according to a specific feature
characterizing this invention, the pump action is limited to a
cooling circuit separated from the general cooling system of the
engine and adapted to cool in particular the supercharging air and
the lubricating oil with more energy than the engine unit as a
whole. According to another feature of this invention a pump of the
annular peripheral induction type is used. Moreover, this invention
provides means for regulating the temperatures in the cooling
circuit as a function of the supercharging pressure, as already
contemplated in the French Pat. application No. 69/22756 of July 4,
1969, so that the circuit temperature be high when the
supercharging pressure is low and the temperature be as low as
possible when the supercharging pressure is high. This arrangement
is applicable to both liquid-cooled engines and direct-flow
air-cooled engines.
The engine proper is cooled as usual by means of a separate
radiator and fan system, in the case of a liquid-cooled engine, and
by means of a fan and separate duct means in the case of engine
cooled by direct-air circulation.
The present invention will now be described with reference to the
attached drawings illustrating diagrammatically by way of example
two typical forms of embodiment of the invention. In the
drawings:
FIG. 1 is a general diagram of the cooling system in the case of an
engine cooled by means of an intermediate liquid fluid;
FIG. 2 is a cross section taken along the line A--A of FIG. 1;
FIG. 3 is a detail section showing the thermostat;
FIG. 4 is a detail section of the pressure-responsive valve,
and
FIG. 5 is a general diagram showing the cooling system in the case
of an engine cooled by direct-air circulation.
Referring first to FIG. 1, the internal combustion engine, in this
case a supercharged Diesel engine, comprises an exhaust pipe 2
through which the gas is directed to the turbine 5 driving in turn
the compressor 6 of the turbo-compressor unit. The supercharger
compressor 6 takes atmospheric air from an inlet 7 and forces same
through a duct 8 leading through a heat exchanger 9 to the pipe 10
supplying combustion air to the engine 1. This engine 1 comprises
an oil pump 11 and an oil filter 12. The oil pump 11 forces oil
through a pipe 13 for lubricating the engine and cooling the
pistons. If desired, part of this oil may also be forced through
another pipe line 14 into a Root supercharger associated with the
engine, for example as disclosed in the Applicants' patent
application Ser. No. 47,331 of June 18, 1970. Finally, the pump 11
is adapted, through another pipe line 15, to supply oil under
pressure to a heat exchanger 16, this oil returning via another
pipe line 17 to the engine sump 18. Both heat exchangers 9 and 16
receive a circulation of cooling liquid therethrough, for example,
water and a glycol additive. This cooling circuit is separate from
the normal or conventional engine water-cooling system illustrated
diagrammatically in the form of a radiator 45 connected through
lines 46 and 47 to the engine cylinder block. In this specific
circuit water accumulates in a reservoir 19 located at the highest
possible level. A water pump 20 draws water through a pipe line 21
and forces same into a pair of branch pipes 22, 23. Pipe 22 extends
through a thermostat 3 of which a detailed view is shown in FIG. 3.
The other pipe 23 extends through a pressure-responsive valve 4 of
which the details are shown in FIG. 4, and pipes 22 and 23 merge
into a common pipe 24 passing firstly through the heat exchanger 9
and then through the other heat exchanger 16, before leading to the
radiator 25; the coolant emerges from radiator 25 and is forced
into reservoir 19. It will be seen that the pressure-responsive
valve 4 is connected via a pipe 27 to the delivery side of
compressor 6.
FIG. 3 illustrates a thermostatic bellows 28 inserted in the pipe
line 22 for controlling the valve 29 in such a manner that the
circuit is closed when the temperature drops below a predetermined
value, for example, 85.degree. C, and open when the temperature is
above this value.
FIG. 4 illustrates a manometric bellow 30 controlling a valve 31
balanced by a spring 32.
A pipe line 27 connects the inner chamber of the manometric bellows
30 to the delivery side of compressor 6; the bellows 30 and spring
32 are gauged so that the valve is normally closed when the
pressure is inferior to 1.4 psi, and wide open when the pressure
value is about 4.2 psi.
Reverting to FIG. 1, it will be seen that the cluster of radiator
25 is cooled by air taken from the outflared upper section 33,
constituting the convergent of a pump 34 having a lower divergent
35.
The induction is produced in this pump by means of the exhaust gas
from the turbine 5 which is directed through a duct 36 tangentially
to an annular chamber 37 as shown in FIG. 2, before penetrating
into the pump through blades 38 illustrated in FIGS. 1 and 2. These
blades 38 are so shaped that the gas stream is eventually rectified
and caused to follow a direction parallel to the generatrices of
the mixing body 34 of the pump. Moreover, the total cross-sectional
area of the annular chamber 37 is small enough to cause the gas to
be accelerated sufficiently for inducing the desired air current.
Of course, this cross-sectional area determines for each gas output
a counterpressure which must be adjusted reasonably in order to
avoid any undesired or abnormal reduction in the power available in
the turbine 5. Thus, the dimensions of the annular chamber 37, the
cross-section of blade-receiving passage and the angular position
of the blades 38 can be selected with a view to obtain a
satisfactory compromise between the induced air input and the noise
level obtained at the exhaust, provided, of course, that a minimum
disturbance is observed at the turbine 5, as already explained
hereinabove. It may be emphasized that by mixing the engine exhaust
gas with a large amount of air there is obtained at the same time a
considerable dilution of the exhaust gas, so that definitely
colourless gas emissions are produced.
The mode of operation of this assembly will be readily inferred
from the above description. However, a few details are given
hereinafter in connection with the functions of the thermostat 3
and the pressure-responsible valve 4.
In case the engine 1 is a conventional Diesel engine simply
supercharged through its turbo-compressor 5, 6, the
pressure-responsive valve 4 and pipes 23, 27 could be dispensed
with so as to maintain only the pipe 22 and thermostat 3 by
adjusting the latter at a relatively low temperature, say, of the
order of 60.degree. or 55.degree. C. In this case the purpose is to
obtain an auxiliary cooling circuit at a general temperature
considerably lower than that of the main engine cooling system 45,
46 and 47. Thus, the supercharging air will under all circumstances
be strongly cooled by the heat exchanger 9, and the lubricating oil
will be strongly cooled by the other heat exchanger 16. The engine
circulation water is kept at about 80.degree. to 85.degree. C. The
chief advantage of providing a separate cooling of the lubricating
oil at a temperature below 60.degree. or 55.degree. C is to relieve
the main radiator 45 since the oil heat is no more dispersed in the
radiator circuit; besides, this oil can thus pick up more heat than
usual from the engine pistons, due to its lower temperature.
Besides, the lower temperature of the supercharging air constitutes
an essential factor for increasing the engine power output without
any excessive strain for the engine parts. Under these conditions
it is clear that, in addition to the advantageous technical results
obtained from the dual point of view of the increased power output
and useful life of the engine, the main radiator is relieved from
excessive work while facilitating the mounting, on a given vehicle,
of a more powerful engine since the main radiator can preserve
reasonable dimensions.
If the engine is a compensated Diesel engine (as disclosed in the
U.S. patent application Ser. No. 794,187 of Jan. 27, 1969), i.e.,
an engine wherein the turbo-compressor 5, 6 is combined with a
variable speed ratio volumetric compressor, a fumigation system,
etc.., the circuit operation is more complicated. In fact, in this
case it is advantageous to use both the thermostat 3 and the
pressure-responsive valve 4. The temperature should be kept as low
as possible in circuit 24 of the cooling system when the engine is
operated under high power output conditions and notably when a high
pressure is obtained on the delivery side of centrifugal compressor
6. The pressure in circuit 24 acts via pipe line 27 on the
pressure-responsive valve 4 to open the branch line 23 so that the
fluid flow be as fast as possible and the radiator 25 operates
under its maximum cooling capacity. It may be emphasized that at
the same time this high-power operation is attended by a very
considerable exhaust gas output at a relatively high pressure so
that the pump 34, 35, 36, 37, 38 operates with a high degree of
efficiency and yields a considerable air throughput across the
radiator 25.
In contrast thereto, when the engine operates at low speed or under
moderate load conditions it is essential that the supercharging air
be at a relatively high temperature and that, consequently, the
circuit 24 be kept at a considerably higher temperature; in this
case the pressure on the delivery side of the centrifugal
compressor is relatively moderate and the pressure-responsive valve
4 is closed. Thus, the fluid can flow only through the branch line
22 as permitted by the thermostat, provided that the temperature is
not inferior to 80.degree.-85.degree. C.
The air flowing through ducts 8 and 10 must in this case be warm,
and the lubricating oil must also preserve a temperature of about
80.degree. C.
The above remarks given in connection with a liquid-cooled engine
are also applicable to an assembly wherein the main engine cooling
circuit operates by direct air flow as in the case shown in FIG. 5.
In this arrangement, as in that illustrated in FIG. 1, there is an
engine 1, an exhaust 2, a turbine 5, a compressor 6, a delivery
duct 8 extending through a heat exchanger 9', but in this case the
exchanger 9' is an air-to-air exchanger provided with fins and
disposed within a duct 39. This arrangement also includes the
lubrication pump 11 and the oil circuit extending through another
heat exchanger 16' of the oil-to-air type provided with fins and
also disposed within the same duct 39. Similarly, the outlet 36 of
turbine 5 is directed tangentially into the circular duct 37 and
acts upon the pump 34, 35, 38 as in the preceding example; the
section 33' of the pump convergent is thus connected not to a
radiator but to the aforesaid duct 39; the air flow sucked by the
pump will thus pass through the upstream portion of the duct 39 in
order to cool directly the heat exchangers 9' and 16'. Of course,
the regulation is effected on the air through a relatively large
by-pass valve shutter 40 which may either close a lateral aperture
49 formed in the wall of duct 39, when it is desired to cause the
air to flow through the heat exchangers, or alternatively tend to
close the main passage of duct 39 when it is desired to prevent the
air from flowing therethrough. In this last case the pump 34, 35,
38 will draw air directly from outside through said aperture 49.
The regulation controls, although applied to an air circulation,
are of the same order as in the preceding case, notably the
thermostatic bellows 28' controlled by the probe 41. This
thermostatic bellows controls the linkage comprising the levers 42,
43 acting in turn upon the valve 40; when the temperature rises and
exceeds a value of, say, 60.degree. C in the lubricating oil, the
thermostat is expanded and, through the levers 42 and 43, tends to
close the aperture 49 by actuating the valve shutter 40 so as to
derive the maximum efficiency from the circulation of air induced
by the pump 34, 35, 38 for cooling the exchangers 9' and 16'.
In the case of an engine equipped with a compensated supercharger
(as disclosed in the aforesaid U.S. patent application Ser. No.
794,187 of Jan. 27, 1969), it is also essential that the
temperature rises when the engine revolves at low speed and under a
moderate load. The pipe line 27' branched off the pipe or duct 8
permits of inducing in the above-described mechanism a correction
also tending to close the duct 39 when only a very low
supercharging pressure is available.
Although a specific form of embodiment and a modification thereof
have been described and illustrated herein, it will readily occur
to those convergent with the art that various modifications and
variations may be brought thereto without departing from the scope
of the present invention.
* * * * *