U.S. patent application number 15/302606 was filed with the patent office on 2017-02-23 for vehicle heat recovery system.
This patent application is currently assigned to Norgen Limited. The applicant listed for this patent is Norgen Limited. Invention is credited to Adam Coker, John Morris, Mark Sealy.
Application Number | 20170051634 15/302606 |
Document ID | / |
Family ID | 50845064 |
Filed Date | 2017-02-23 |
United States Patent
Application |
20170051634 |
Kind Code |
A1 |
Sealy; Mark ; et
al. |
February 23, 2017 |
VEHICLE HEAT RECOVERY SYSTEM
Abstract
A system for an engine (101) comprises a heat recovery system
and a gaseous fuel supply system. The heat recovery system
comprises a first reservoir (104) for fluid, at least one
evaporator (121) for transferring heat from an engine to the fluid,
a vapour expander (129) for converting fluid vapour energy into
motive power, and a condenser (134). The gaseous fuel supply system
comprises a second reservoir (90) for liquefied gaseous fuel and a
fuel evaporator (91) for expanding liquefied gaseous fuel into
gaseous fuel for the engine. The condenser (134) is in thermal
contact with the fuel evaporator (91).
Inventors: |
Sealy; Mark; (Alcester,
GB) ; Coker; Adam; (Johnson, IN) ; Morris;
John; (Auburn, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Norgen Limited |
Lichfield |
|
GB |
|
|
Assignee: |
Norgen Limited
Lichfield
GB
|
Family ID: |
50845064 |
Appl. No.: |
15/302606 |
Filed: |
April 13, 2015 |
PCT Filed: |
April 13, 2015 |
PCT NO: |
PCT/GB2015/051115 |
371 Date: |
October 7, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02M 21/06 20130101;
Y02T 10/12 20130101; Y02T 10/16 20130101; F01K 23/065 20130101;
Y02T 10/126 20130101; F01K 21/045 20130101; F02M 31/18 20130101;
Y02T 10/32 20130101; Y02T 10/30 20130101; F01K 25/08 20130101; Y02E
20/16 20130101 |
International
Class: |
F01K 23/06 20060101
F01K023/06; F01K 25/08 20060101 F01K025/08 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 2014 |
GB |
1406803.5 |
Claims
1. A system for an engine comprising: a heat recovery system
comprising: a first reservoir for fluid; at least one evaporator
for transferring heat from an engine to the fluid, the evaporator
having an evaporator outlet and an evaporator inlet in fluid
communication with the first reservoir; a vapour expander for
converting fluid vapour energy into motive power, the vapour
expander having a vapour expander outlet and a vapour expander
inlet in fluid communication with the evaporator outlet; a
condenser having a condenser inlet in fluid communication with the
vapour expander outlet and a condenser outlet in fluid
communication with the first reservoir; and a gaseous fuel supply
system comprising: a second reservoir for liquefied gaseous fuel
and having a reservoir outlet; and a fuel evaporator for expanding
liquefied gaseous fuel into gaseous fuel for an engine, the liquid
expander having a liquid expander inlet in fluid communication with
the reservoir outlet; wherein the condenser is in thermal contact
with the fuel evaporator.
2. System according to claim 1, wherein the gaseous fuel is natural
gas.
3. System according to claim 1, wherein the fluid is primarily a
hydrocarbon.
4. System according to claim 3, wherein the fluid is primarily
ethanol.
5. An engine system comprising: a combustion engine; a heat
recovery system comprising: a first reservoir for fluid; at least
one evaporator for transferring heat from the engine to a fluid,
the evaporator having an evaporator outlet and an evaporator inlet
in fluid communication with the first reservoir; a vapour expander
for converting fluid vapour energy into motive power, the vapour
expander having a vapour expander outlet and a vapour expander
inlet in fluid communication with the evaporator outlet; a
condenser having a condenser inlet in fluid communication with the
vapour expander outlet and a condenser outlet in fluid
communication with the first reservoir; and a gaseous fuel supply
system comprising: a second reservoir for liquefied gaseous fuel
and having a reservoir outlet; and a fuel evaporator for expanding
liquefied gaseous fuel into gaseous fuel and having a liquid
expander inlet in fluid communication with the reservoir outlet and
a liquid expander outlet in fluid communication with the engine;
wherein the condenser is in thermal contact with the fuel
evaporator.
6. Engine system according to claim 5, wherein the gaseous fuel is
natural gas.
7. Engine system according to claim 5, wherein the fluid is
primarily a hydrocarbon.
8. Engine system according to claim 7, wherein the fluid is
primarily ethanol.
9. A system for an internal combustion engine comprising: a heat
recovery system comprising: a first reservoir of fluid; at least
one evaporator for transferring heat from an engine to the fluid,
the evaporator having an evaporator outlet and an evaporator inlet
in fluid communication with the first reservoir; a vapour expander
for converting fluid vapour energy into motion, the vapour expander
having a vapour expander outlet and a vapour expander inlet in
fluid communication with the evaporator outlet; and a condenser
having a condenser inlet in fluid communication with the vapour
expander outlet and a condenser outlet in fluid communication with
the first reservoir; and a gaseous fuel supply system for an engine
comprising a second reservoir; and at least one flow path for
supply into the engine, for combustion, of fluid in liquid or
gaseous form from the heat recovery system in addition to gaseous
fuel from the gaseous fuel supply system.
10. System according to claim 9, wherein the gaseous fuel is
natural gas.
11. System according to claim 9, wherein the fluid is a primarily
hydrocarbon.
12. System according to claim 11, where in the fluid is primarily
ethanol.
13. An engine system comprising: an engine; a heat recovery system
comprising: a first reservoir of fluid; at least one evaporator for
transferring waste heat from the engine to the fluid, the
evaporator having an evaporator outlet and an evaporator inlet in
fluid communication with the first reservoir; a vapour expander for
converting fluid vapour energy into motion, the vapour expander
having a vapour expander outlet and a vapour expander inlet in
fluid communication with the evaporator outlet; a condenser having
a condenser inlet in fluid communication with the vapour expander
outlet and a condenser outlet in fluid communication with the first
reservoir; and a gaseous fuel supply system comprising a second
reservoir; and at least one flow path for supply into the engine,
for combustion, of fluid in liquid or gaseous form from the heat
recovery system in addition to gaseous fuel from the gaseous fuel
supply system.
14. Engine system according to claim 13, wherein the gaseous fuel
is natural gas.
15. Engine system according to claim 13, wherein the fluid is
primarily a hydrocarbon.
16. Engine system according to claim 15, wherein the fluid is
primarily ethanol.
17. Engine system according to any one of claim 13, wherein the
system comprises a fuel evaporator for expanding liquefied gaseous
fuel into gaseous fuel, the condenser being in thermal contact with
the fuel evaporator.
Description
TECHNICAL FIELD
[0001] The embodiments described below relate to heat recovery (HR)
systems, and more particularly, to a vehicle heat recovery system
applied to a non-diesel internal combustion engine, particularly
but not exclusively a natural gas internal combustion engine.
BACKGROUND OF THE INVENTION
[0002] The use of natural gas to fuel internal combustion (IC)
engines, as opposed to using gasoline or diesel fuels, is becoming
more common. The incentives include lower fuel costs and reduced
emissions. However there are drawbacks to using natural gas which
can include an increase in the space required for carrying fuel and
a loss of performance compared to an equivalent diesel vehicle. It
is also common that the thermal efficiency of a natural gas engine
(especially for homogeneous combustion) is lower than an equivalent
diesel engine and that engine out exhaust temperatures are
correspondingly higher. It is also common for natural gas engines
to require less complex after-treatment equipment than an
equivalent diesel engine to meet current emissions standards (for
example no SCR) meaning the tail pipe exhaust temperatures are
typically much higher than for an equivalent diesel vehicle.
[0003] Further, it is increasingly common for natural gas to be
stored in a liquid state (Liquified Natural Gas, LNG) on vehicles
to maximize the range. The liquid gas is normally evaporated to gas
before entering the engine which requires considerable heat
input.
[0004] It is also known to recover heat energy from a conventional
vehicle IC engine using a Rankine cycle. For example, U.S. Pat. No.
4,031,705 discloses a heat recovery system that heats the working
fluid using heat from the IC engine's exhaust and the IC engine's
cooling circuit, i.e., the IC engine's radiator.
DISCLOSURE OF THE INVENTION
[0005] According to a first aspect of the invention, there is
provided a system for an engine comprising: [0006] a heat recovery
system comprising: [0007] a first reservoir for fluid; [0008] at
least one evaporator for transferring heat from an engine to the
fluid, the evaporator having an evaporator outlet and an evaporator
inlet in fluid communication with the first reservoir; [0009] a
vapour expander for converting fluid vapour energy into motive
power, the vapour expander having a vapour expander outlet and a
vapour expander inlet in fluid communication with the evaporator
outlet; [0010] a condenser having a condenser inlet in fluid
communication with the vapour expander outlet and a condenser
outlet in fluid communication with the first reservoir; and [0011]
a gaseous fuel supply system comprising: [0012] a second reservoir
for liquefied gaseous fuel and having a reservoir outlet; and
[0013] a fuel evaporator for expanding liquefied gaseous fuel into
gaseous fuel for an engine, the liquid expander having a liquid
expander inlet in fluid communication with the reservoir outlet;
[0014] wherein the condenser is in thermal contact with the fuel
evaporator.
[0015] Preferably, the gaseous fuel is natural gas.
[0016] Preferably, the fluid is primarily a hydrocarbon, in
particular ethanol.
[0017] According to a second aspect of the present invention, there
is provided an engine system comprising: [0018] a combustion
engine; [0019] a heat recovery system comprising: [0020] a first
reservoir for fluid; [0021] at least one evaporator for
transferring heat from the engine to a fluid, the evaporator having
an evaporator outlet and an evaporator inlet in fluid communication
with the first reservoir; [0022] a vapour expander for converting
fluid vapour energy into motive power, the vapour expander having a
vapour expander outlet and a vapour expander inlet in fluid
communication with the evaporator outlet; [0023] a condenser having
a condenser inlet in fluid communication with the vapour expander
outlet and a condenser outlet in fluid communication with the first
reservoir; and [0024] a gaseous fuel supply system comprising:
[0025] a second reservoir for liquefied gaseous fuel having a
reservoir outlet; and [0026] a fuel evaporator for expanding
liquefied gaseous fuel into gaseous fuel for an engine having a
liquid expander inlet in fluid communication with the reservoir
outlet and a liquid expander outlet in fluid communication with the
engine; [0027] wherein the condenser is in thermal contact with the
fuel evaporator.
[0028] Preferably, the gaseous fuel is natural gas.
[0029] Preferably, the fluid is primarily a hydrocarbon, in
particular ethanol.
[0030] According to a third aspect of the invention, there is
provided a system for an internal combustion engine comprising:
[0031] a heat recovery system comprising: [0032] a first reservoir
of fluid; [0033] at least one evaporator for transferring heat from
an engine to the fluid, the evaporator having an evaporator outlet
and an evaporator inlet in fluid communication with the first
reservoir; [0034] a vapour expander for converting fluid vapour
energy into motive power, the vapour expander having a vapour
expander outlet and a vapour expander inlet in fluid communication
with the evaporator outlet; and [0035] a condenser having a
condenser inlet in fluid communication with the vapour expander
outlet and a condenser outlet in fluid communication with the first
reservoir; and [0036] a gaseous fuel supply system for an engine
comprising a second reservoir; and [0037] at least one flow path
for supply into the engine, for combustion, of fluid in liquid or
gaseous form from the heat recovery system in addition to gaseous
fuel from the gaseous fuel supply system.
[0038] Such a combination of a natural gas engine vehicle in
combination with a heat recovery system where the heat recovery
working fluid is also consumed via combustion in combination with
the natural gas is advantageous in terms of reduced risk of working
fluid degradation over time. Moreover, such co-fuelling may assist
the ignition of natural gas in-cylinder and increase vehicle
range.
[0039] Preferably, the gaseous fuel is natural gas.
[0040] Preferably, the fluid is a hydrocarbon, in particular
ethanol.
[0041] The system may comprise a fuel evaporator for expanding
liquefied gaseous fuel into gaseous fuel, the condenser being in
thermal contact with the fuel evaporator. This may reduce the
requirement for heat rejection in the heat recovery system.
[0042] According to a fourth aspect of the present invention, there
is provided an engine system comprising: [0043] an engine; [0044] a
heat recovery system comprising: [0045] a first reservoir of fluid;
[0046] at least one evaporator for transferring heat from the
engine to a fluid, the evaporator having an evaporator outlet and
an evaporator inlet in fluid communication with the first
reservoir; [0047] a vapour expander for converting fluid vapour
energy into motion, the vapour expander having a vapour expander
outlet and a vapour expander inlet in fluid communication with the
evaporator outlet; [0048] a condenser having a condenser inlet in
fluid communication with the vapour expander outlet and a condenser
outlet in fluid communication with the first reservoir; and [0049]
a gaseous fuel supply system comprising a second reservoir; and
[0050] at least one flow path for supply into the engine, for
combustion, of fluid in liquid or gaseous form from the heat
recovery system in addition to gaseous fuel from the gaseous fuel
supply system.
[0051] Preferably, the gaseous fuel is natural gas.
[0052] Preferably, the fluid is a hydrocarbon, in particular
ethanol.
[0053] The system may comprise a fuel evaporator for expanding
liquefied gaseous fuel into gaseous fuel, the condenser being in
thermal contact with the fuel evaporator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 shows a schematic of a heat recovery system for an
engine according to a first embodiment.
[0055] FIG. 2 shows a schematic of a heat recovery system for an
engine according to a second embodiment.
[0056] FIG. 3 shows a schematic of a heat recovery system for an
engine according to a third embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0057] The figures and following description depict specific
examples to teach those skilled in the art how to make and use the
best mode of embodiments of a vehicle heat recovery system. For the
purpose of teaching inventive principles, some conventional aspects
have been simplified or omitted. Those skilled in the art will
appreciate variations from these examples that fall within the
scope of the present description. Those skilled in the art will
appreciate that the features described below can be combined in
various ways to form multiple variations of the vehicle heat
recovery system. As a result, the embodiments described below are
not limited to the specific examples described below, but only by
the claims and their equivalents.
[0058] FIG. 1 shows a schematic of a heat recovery system 100 for
an engine 101 according to a first embodiment. The heat recovery
system 100 may be implemented for an engine 101 of a motor vehicle
(not shown). The vehicle may be an on-road truck, the operation of
which is set out in the standard `highway cycle` or World
Harmonised Test Cycle (WHTC).
[0059] As shown, the engine 101 is a gas-fuelled internal
combustion (IC) engine having pistons that reciprocate in cylinders
as indicated at 99 to drive a crankshaft 102. A fan 135 may be
coupled to the crankshaft to generate air flow across a radiator
136 for the engine cooling system.
[0060] The gas fuel typically natural gas--is stored in compressed
liquid form in storage tank 90 from where it is fed (as indicated
by arrow F) via a liquid-to-gas evaporator 91 to mix as indicated
at 98 with air A supplied by a turbocharger 92, charge cooler 93
and flow valve 94 prior to being fed into the cylinders 99 as is
well known.
[0061] As is also well known, exhaust from the cylinders is
recirculated (EGR) to the engine inlet 103 via EGR flow path 95
and/or fed to the turbocharger 92 and then via treatment system 96
(SCR) and an exhaust flow path/tail pipe 97 to atmosphere E. As
shown, treatment system 96 does not employ active regeneration and
thus avoids excessive tail pipe temperatures.
[0062] First and second evaporators 120, 121 are located within
exhaust flow path 97 and EGR flow path 95 respectively. As
indicated by arrows W, working fluid is fed to each evaporator from
a reservoir or fluid supply 104 via a high-pressure fluid pump 105
in fluid communication with an outlet of the fluid supply 104. The
working fluid may include water, refrigerant or ethanol and
possibly oil. The number of evaporators utilized is not important
for purposes of the present description and should in no way limit
the scope of the claims that follow.
[0063] The high-pressure fluid pump 105 may be driven by the engine
101 or may be driven by a separate electric motor, for example. The
high-pressure fluid pump 105 can elevate the pressure of the fluid
from a reservoir pressure to a higher threshold pressure. In some
embodiments, the high-pressure fluid pump 105 may raise the
pressure of the fluid to a threshold pressure of approximately 30
bar from the reservoir pressure, which is typically at or slightly
above atmospheric pressure. However, other threshold pressures are
certainly possible and the particular example pressure should in no
way limit the scope of the present embodiment.
[0064] Heat from the exhaust in the two flow paths 95,97 (which may
be at different temperatures) is transferred via evaporators
120,121 to the working fluid, which vaporizes and may become
superheated, e.g. at approximately 250.degree. C. and 25 bar.
However, those skilled in the art can readily appreciate that these
values may vary based on the particular application and should in
no way limit the scope of the present embodiment.
[0065] The vapor leaves the two evaporators 120,120 and flows (as
indicated by arrows X) to an expander 129 where it reduces in
enthalpy while expanding, thereby converting at least some of the
energy of the vapor to mechanical work/motive power, specifically
motion. The expander 129 can comprise one of a variety of
well-known devices, such as a turbine, a piston, a vapor engine,
such as a rotary vane type vapor engine, etc. The particular type
of expander 129 utilized is not important for purposes of the
present description and should in no way limit the scope of the
claims that follow.
[0066] In the embodiment shown, the output shaft of expander 129 is
coupled as indicated at 131 to the crankshaft 102 or other suitable
component of the engine 101 in order that the motion of the output
shaft might drive the crankshaft, adding power to the engine
101.
[0067] As shown, the expanded working fluid leaves the expander 129
and travels to a condenser 134 where it is cooled to liquid form
prior to being delivered back to the fluid reservoir 104 as
indicated by arrow R. Condenser 134 is in thermal contact with the
fuel liquid-to-gas evaporator 91 such that the heat released by the
cooling working fluid is transferred to the expanding liquid fuel
gas. The thermal contact may be direct physical contact, with
condenser and evaporator being fixed to or even integral with one
another or indirect contact, e.g. through a shared heat transfer
medium such as a liquid coolant.
[0068] FIG. 2 shows a schematic of a heat recovery system 100 for
an engine 101 according to a second embodiment and differing from
the first embodiment by a working fluid that is combustible and
which not only circulates (as indicated by arrows W, X and R)
around the heat recovery circuit comprising reservoir 104, pump
105, evaporators 120,121, expander 129 and condenser 134 but which
is also fed in liquid or gaseous form (as indicated by arrow Y) via
line 200 into the engine inlet 103 alongside air A and gas F to
burn in the engine cylinders 99.
[0069] This offers a convenient way of disposing of the working
fluid before it reaches the end of its thermodynamically useful
life (organic working fluids in particular break down with repeated
exposure to the high temperatures in the evaporators). In
particular, it can allow the use of shorter life or more
heat-sensitive working fluids. Reservoir 104 can be replenished
with working fluid at the same time as the storage tank 90 is
replenished with liquified gas. A hydrocarbon, in particular
ethanol, may be a suitable working fluid. In the case of a motor
vehicle, using the working fluid as an additional fuel source will
also increase the range of the vehicle between refueling stops.
[0070] Moreover, the working fluid can also provide combustion
assistance to the gas: in particular, when diesel engines are
converted to run on natural gas, they are often equipped with spark
ignition systems or co-fuelled with a compression ignition fuel in
order to run. The working fluid can assist fuel ignition. This may
be particularly relevant also for cold starting. A hydrocarbon, in
particular ethanol, may be suitable for this purpose.
[0071] FIG. 3 shows a schematic of a heat recovery system 100 for
an engine 101 according to a third embodiment. Not only does the
working fluid F from reservoir 104 circulate (as indicated by
arrows W, X and R) around the heat recovery circuit comprising
evaporators 120,121, expander 129 and condenser 134, it also serves
as the sole fuel, injected (as indicated by arrow Y) either as a
liquid via line 200 into the engine inlet 103 alongside air A
and/or as a vapour via line 3 also into the engine inlet 103
alongside air A.
[0072] Not only does this offer a convenient way of disposing of
the working fluid before it reaches the end of its
thermodynamically-useful life, potentially allowing short-life or
more thermally-sensitive working fluids to be used, it also reduces
the number of different fluids, reduces the need for cooling and
reduces complexity.
[0073] Although specific embodiments are described herein for
illustrative purposes, various equivalent modifications are
possible within the scope of the present description, as those
skilled in the relevant art will recognize. The teachings provided
herein can be applied to other heat recovery systems, and not just
to the embodiments described above and shown in the accompanying
figures. Accordingly, the scope of the embodiments described above
should be determined from the following claims.
* * * * *