U.S. patent application number 11/520464 was filed with the patent office on 2008-03-13 for coolant system for hybrid power system.
This patent application is currently assigned to Cummins Power Generation Inc.. Invention is credited to Allen B. Carney, Tommy J. Harder, David A. Overland, Bradley D. Padget.
Application Number | 20080060590 11/520464 |
Document ID | / |
Family ID | 39168298 |
Filed Date | 2008-03-13 |
United States Patent
Application |
20080060590 |
Kind Code |
A1 |
Carney; Allen B. ; et
al. |
March 13, 2008 |
COOLANT SYSTEM FOR HYBRID POWER SYSTEM
Abstract
A cooling system for a hybrid power system that includes an
engine such as a generator engine, and a power converter such as an
inverter, includes an engine cooling circuit, a power converter
cooling circuit and a common coolant tank operatively coupled to
both the engine and the power converter via the engine cooling
circuit and the power converter cooling circuit respectively.
Inventors: |
Carney; Allen B.; (Vadnais
Heights, MN) ; Harder; Tommy J.; (New Richmond,
WI) ; Overland; David A.; (East Bethel, MN) ;
Padget; Bradley D.; (Richfield, MN) |
Correspondence
Address: |
HAMRE, SCHUMANN, MUELLER & LARSON, P.C.
P.O. BOX 2902
MINNEAPOLIS
MN
55402-0902
US
|
Assignee: |
Cummins Power Generation
Inc.
Minneapolis
MN
|
Family ID: |
39168298 |
Appl. No.: |
11/520464 |
Filed: |
September 13, 2006 |
Current U.S.
Class: |
123/41.54 ;
123/41.27; 123/41.31 |
Current CPC
Class: |
F01P 11/029
20130101 |
Class at
Publication: |
123/41.54 ;
123/41.27; 123/41.31 |
International
Class: |
F01P 9/02 20060101
F01P009/02; F01P 1/06 20060101 F01P001/06; F01P 3/22 20060101
F01P003/22 |
Claims
1. A cooling system comprising: an engine; an engine cooling
circuit to deliver coolant to the engine; a power converter; a
power converter cooling circuit to deliver coolant to the power
converter; and a coolant tank operatively coupled to both the
engine cooling circuit and the power converter cooling circuit, p1
the coolant tank including an overflow inlet port configured to
receive coolant overflow from the engine, the coolant tank further
having a coolant inlet port configured to receive coolant ftom the
power converter cooling circuit and further having a coolant outlet
port configured to deliver coolant to the power converter cooling
circuit the coolant tank further having a first chamber leading to
the coolant outlet port and a second chamber configured to receive
coolant via the coolant inlet port, wherein the first chamber and
the second chamber are senarated by a wall, the coolant inlet port
being at a bottom portion of the second chamber.
2. The cooling system according to claim 1, wherein the coolant
tank holds engine coolant overflow and also operates as an
expansion and pressure head tank for the power converter cooling
circuit.
3. The cooling system according to claim 1, wherein the engine is
configured to develop electrical energy.
4. The cooling system according to claim 1, wherein the power
converter is coupled to a bank of DC batteries.
5. The cooling system according to claim 1, wherein the power
converter and engine are operatively coupled to an electrical
energy delivery system.
6. The cooling system according to claim 1, wherein the coolant
tank includes an input from a radiator, the radiator located
between the engine and the coolant tank.
7. The cooling system according to claim 6, wherein the coolant
tank includes an outlet to a pump to drive coolant through the
power converter cooling circuit, the coolant tank further including
an inlet from the power converter cooling circuit.
8. The cooling system according to claim 7, wherein the pump is
located at a lower elevation than the coolant tank.
9. The cooling system according to claim 7, wherein a coolant hose
leading to the coolant tank inlet includes a coolant trap.
10. The cooling system according to claim 1, wherein the power
converter comprises an inverter operational to convert DC current
to AC current.
11. A cooling system comprising a coolant tank including an
overflow inlet port configured to receive coolant overflow from an
engine, the coolant tank further having a coolant inlet port
configured to receive coolant from a power converter cooling
circuit and further having a coolant outlet port configured to
deliver coolant to the power converter cooling circuit, the coolant
tank further having a first chamber leading to the coolant outlet
port and a second chamber configured to receive coolant via the
coolant inlet port, wherein the first chamber and the second
chamber are separated by a wall.
12. The cooling system according to claim 11, wherein the coolant
tank further includes a filling inlet to fill with coolant.
13. The cooling system according to claim 11, wherein the wall has
a height of at least two inches.
14. The cooling system according to claim 11, wherein coolant
outlet port is at a bottom portion of the first chamber.
15. A cooling system comprising: an engine; an engine cooling
circuit to deliver coolant to the engine; a power converter; a
power converter cooling circuit including a coolant pump to deliver
coolant to the power converter; and a coolant tank operatively
coupled to both the engine cooling circuit and the power converter
cooling circuit, wherein the pump is located at a lower elevation
than the coolant tank, wherein the tank holds engine coolant
overflow and operates as an expansion and pressure head tank for
the power converteo cooling circuit.
16. (canceled)
17. The cooling system according to claim 15, wherein the coolant
tank includes an input from a radiator, the radiator between the
engine and the coolant tank.
18. The cooling system according to claim 15, wherein the coolant
tank includes an outlet to the pump to drive coolant through the
power converter cooling circuit, the coolant tank further including
an inlet from the power converter cooling circuit.
19. The cooling system according to claim 18, wherein a coolant
hose leading to the coolant tank inlet includes a coolant trap.
20. The cooling system according to claim 15, wherein the engine is
a generator engine and further wherein the power converter is an
inverter operational to convert DC current to AC current.
21. (canceled)
22. The cooling system according to claim 11, wherein coolant inlet
port is at a bottom portion of the second chamber.
23. The cooling system according to claim 11, wherein the second
chamber having an opening and being connected to the coolant inlet
port at the opening, the opening being above a height of the wall.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the field of power generating
systems, and more specifically to a coolant system for a vehicular
hybrid power system.
[0003] 2. Description of the Prior Art
[0004] A typical vehicular hybrid power system utilizes both a
battery stack and a generator engine assembly to develop electrical
power. The battery stack can typically be charged from either the
generator engine assembly or from shore power. The hybrid system
can be used, for example, to generate electrical power for a
vehicle such as a recreational vehicle (RV). When utilizing such a
hybrid power system onboard a vehicle, problems can arise with the
need for cooling the hybrid power system components. Manufacturing
costs, maintenance costs, and space requirements are factors that
need to be optimized for such a system.
SUMMARY OF THE INVENTION
[0005] A vehicular hybrid power system generally includes an engine
driven electrical power generator and a bank of batteries to
provide a dual source of electrical power, and a power conversion
assembly such as, but not limited to, an inverter for converting DC
power to AC power. The present invention provides a cooling system
that includes a coolant tank operatively coupled to both the
generator engine and the inverter assembly. The coolant tank
performs a dual function by acting as a generator engine coolant
overflow reservoir and as an expansion and pressure head tank for
an inverter assembly cooling circuit. The cooling system further
employs access to cooling air provided by the engine driven
electrical power generator with a heat exchanger and a liquid
coolant pumping system to transfer cooling liquid via hoses between
the inverter assembly and the engine driven electrical power
generator.
[0006] The liquid coolant pumping system is turned off during modes
when it is unnecessary to cool the inverter assembly, as the
inverter assembly is a parasitic load to the available user
electrical power. If no coolant is available for pumping, energy
management system controls provide a warning or fault condition
depending upon predetermined temperatures. The liquid coolant
pumping system is turned on whenever predetermined temperatures in
the inverter assembly reach desired temperature threshold
values.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Other aspects, features and advantages of the present
invention will be readily appreciated as the invention becomes
better understood by reference to the following detailed
description when considered in connection with the accompanying
drawing figures wherein:
[0008] FIG. 1 is a schematic representation of a hybrid power
system including a cooling system for the hybrid power system that
includes a common liquid cooling tank, in accordance with one
embodiment;
[0009] FIG. 2 is a schematic view of a portion of the hybrid power
system and its associated cooling system shown in FIG. 1;
[0010] FIG. 3 is a perspective view of the portion of the hybrid
power system and its associated cooling system shown in FIG. 2;
and
[0011] FIG. 4 shows a side view of a coolant tank suitable for use
with the hybrid power system shown in FIGS. 1-3, in accordance with
one embodiment.
[0012] While the above-identified drawing figures set forth
particular embodiments, other embodiments of the present invention
are also contemplated, as noted in the discussion. In all cases,
this disclosure presents illustrated embodiments of the present
invention by way of representation and not limitation. Numerous
other modification and embodiments can be devised by those skilled
in the art which fall within the scope and spirit of the principles
of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] FIG. 1 shows a schematic representation of a vehicular
hybrid power system and a cooling system 110 for cooling portions
of the hybrid power system, in accordance with one embodiment. The
hybrid power system is shown integrated within an RV 100. Other
embodiments can utilize such a hybrid power system in other types
of vehicles, such as, but not limited to, watercraft and aircraft
vehicles. Cooling system 110 is particularly configured to cool
designated portions of the hybrid power system that includes, for
example, an engine generator unit 105, a battery bank 120, and a
power converter, such as but not limited to, an inverter assembly
140. The hybrid power system also can be seen to include an input
for shore power 145. These hybrid power system components are
operatively coupled to develop and manage the power requirements of
RV 100.
[0014] In one embodiment, engine generator unit 105 can include a
variable speed engine 130 and be designed to deliver a desired
amount of energy. Generator engine 130 receives fuel such as
diesel, natural gas or liquid propane vapor through an intake.
Generator engine 130 is coupled to an alternator (not shown) such
that as a crankshaft is rotated by the operation of engine
generator 130, the crankshaft drives the alternator which, in turn,
converts the mechanical energy generated by generator engine 130 to
electrical power for transmission and distribution throughout the
RV 100.
[0015] Cooling system 110 further includes a radiator 202
operatively connected to generator engine 130 such that engine
coolant from generator engine 130 circulates through radiator 202
during operation of generator engine 130. Air passes over the
radiator 202 so as to effectuate a heat exchange between generator
engine coolant flowing through radiator 202 and the air. In order
to draw air over radiator 202, cooling system 110 can include a fan
(not shown) to draw air across radiator 202 so as to cool generator
engine 130 and the engine coolant flowing through the radiator
202.
[0016] Battery bank 120 can include any desired number, typically
six or more 12V batteries located at a rear portion of the RV 100.
These batteries deliver, for example, a nominal 12 V DC to power
converter/inverter assembly 140 which converts the DC to AC power
to help power the energy load required by RV 100, along with the
energy supplied via the engine generator unit 105. The power from
inverter assembly 140 and the engine generator unit 105 is managed
by an energy management system control assembly 142 that helps
store, manage, and deliver the energy load requirements of the RV
100.
[0017] A hybrid power system such as depicted in FIG. 1 requires
extensive cooling since the heat level developed by inverter
assembly 140 and generator engine 130 can be very high. In this
embodiment, inverter assembly 140 is designed with a cooling plate
144. Cooling plate 144 receives coolant from the front portion of
the RV 100 via a coolant line such as a hose 152. Cooling plate 144
is incorporated into inverter assembly 140 and is adapted to
provide enough cooling to allow the use of the inverter assembly
140 in the hybrid power system. In this embodiment, inverter
assembly 140 is most preferably located near the battery bank 120,
which traditionally resides in the rear portion of Class A coaches,
such as RV 100, while the engine generator unit 105 has
traditionally been located in the undercarriage slide-out at the
front of the RV 100. Accordingly, coolant flows to the inverter
assembly 140 via coolant hose 152 and back to a heat exchanger 204
via coolant hose 154.
[0018] FIG. 2 is a schematic view illustrating the engine generator
cooling system 150; and FIG. 3 is a perspective view of the engine
generator cooling system 150 shown in FIG. 2. Engine generator
cooling system 150 utilizes the access to the cooling air provided
to generator engine radiator 202 along with a heat exchanger 204
and a pump 206, and transfers the cooling liquid using hoses 152
and 154 to and from inverter assembly 140 such as depicted in FIG.
1 to the frontally mounted engine generator unit 105.
[0019] Engine generator cooling system 150 generally includes
generator engine radiator 202, heat exchanger 204, a coolant pump
206, and a coolant tank 208. Engine generator cooling system 150 is
designed such that the single coolant tank 208 is operatively
coupled to both the generator engine 130 and the inverter assembly
140 such as depicted in FIG. 1. This allows for space saving within
the front of RV 100 and provides both, manufacturing and
maintenance advantages including, but not limited to, for example,
the elimination of any necessity to provide undesirably large
current carrying capacity power cables.
[0020] In one embodiment, for example, coolant flows in a first
cooling circuit between generator engine 130 and generator engine
radiator 202 with coolant overflow being directed to coolant tank
208 via an overflow hose 207. In a second cooling circuit, coolant
to the inverter assembly 140, such as depicted in FIG. 1, flows
from coolant tank 208 through coolant pump 206, through heat
exchanger 204 and back to the inverter assembly 140 via hose 152
and back to the coolant tank 208 via hose 154, which is coupled to
coolant tank 208.
[0021] In one embodiment, coolant pump 206 is positioned below
coolant tank 208 such that pump 206 has a head pressure when the
pump 206 is first turned on. The location of pump 206 thus
facilitates system filling via a non self-priming pump.
[0022] Heat exchanger 204 receives coolant from the pump 206. A fan
309, shown in FIG. 3, can be used in some embodiments to provide
further cooling within heat exchanger 204.
[0023] Accordingly, coolant tank 208 performs a dual purpose by
acting as a generator engine coolant overflow for the generator
engine cooling circuit and acting as an expansion and pressure head
tank for the inverter assembly cooling circuit.
[0024] In one embodiment, upstream coolant return hose 154 includes
a coolant trap 210. For example, return hose 154 can include an
excess length of hose in order to form a trap for the coolant, such
as a J-trap. Trap 210 can contain the amount of fluid available to
the generator engine 130 suitable for testing purposes. This allows
the generator engine 130 to be tested before shipping, and then if
any coolant is sloshed out of the tank 208 and into the coolant
hose 154 during shipping, the trap 210 will contain the coolant. On
the other hand, heat exchanger 204 acts a trap downstream of tank
208. Accordingly, an operator at the OEM should see little if any
coolant liquid upon removal of hose plugs that may be employed as a
maintenance feature associated with coolant hoses 152, 154.
Accordingly, the engine generator cooling system 150 includes means
to utilize overflow functions and to maintain a dry header tank for
assembly and testing purposes.
[0025] FIG. 4 shows a side view of coolant tank 208, in accordance
with one embodiment. As discussed, coolant tank 208 is a common
tank used for both generator engine 130 coolant overflow and
inverter assembly 140 electronics cooling as well as an expansion
and pressure head tank for the inverter assembly 140 cooling
circuit. Again, this advantageously saves both space and money. In
one embodiment, coolant tank 208 includes a molded plastic body
defining an internal reservoir 401. The internal reservoir 401 is
divided into an upper common volume or chamber 403 and two lower
divided volumes or chambers 404 and 406, which are divided by a
wall, such as dam 402. In use, coolant leaves tank 208 to cool the
inverter assembly cooling circuit through outlet 408 and returns
through inlet 410. Outlet 408 is at the bottom of first chamber 404
and inlet 410 feeds coolant into second chamber 406.
[0026] Tank 208 includes enough volume in the second coolant
chamber 406 to allow for expansion of the volume of fluid required
by the generator engine 130 (for example, fluid in the generator
engine block, radiator 202, and hoses). Thus, as the coolant
expands with temperature, the excess fluid enters chamber 406 of
the tank 208. If more comes in, it can overflow dam 420 into
chamber 404 or merely fill up more of the common volume area 403.
However, if any of the inverter assembly cooling circuit coolant
hoses leak somewhere in the system, the generator engine 130 will
never be without coolant because of chamber 406 and dam 402, since
the amount of coolant in chamber 406 will be prevented from
entering the inverter coolant cooling circuit though outlet 408.
Moreover, extra chamber 406 allows the generator engine 130 to be
tested before leaving the plant. This is because the entire system
does not need to be filled with coolant, other than just enough to
run the generator engine 130. Then as noted above, when an OEM gets
the system, the coolant will either be in tank 208 or maybe in the
coolant trap 210 discussed above.
[0027] In one embodiment, tank 208 includes a cap to seal the tank
at a fill port 420. To test the system, tank 208 is pressurized
through the overflow hose 207 depicted in FIGS. 2 and 3. The
pressure is then removed so that tank 208 is able to operate at
atmospheric pressure. The inlet and outlet ports 408 and 410 are
plugged during assembly and removed by the OEM operator.
[0028] Moreover, referring again to FIGS. 1, 2, and 3, the 3-D
footprint of the present cooling design allows for ease of
maintenance and service. For example, the system is designed and
laid out such that items requiring service are located at the
bottom of the system. These include pump 206, radiator 204 and
hoses 154 and 152, for example. Conversely, maintenance items are
located at the easily accessible top portion of the system. These
include the fill portions inputs of radiator 202 and overflow tank
280, for example. Thus, the layout provides ease of service and
maintenance within a small overall 3-D footprint.
TABLE-US-00001 Full Coolant Empty Coolant System System Temp (C)
Volt (V) Current (A) Current (A) 75 14.5 3.75 1.93 75 10.45 2.53
1.76 -20 14.5 4.03 2.41 -20 10.5 3.00 2.31
[0029] The above description is intended to be illustrative, and
not restrictive. Many other embodiments will be apparent to those
of skill in the art upon reviewing the above description. The scope
of the invention should, therefore, be determined with reference to
the appended claims, along with the full scope of equivalents to
which such claims are entitled.
* * * * *