U.S. patent application number 14/366317 was filed with the patent office on 2014-11-13 for hydraulic transport refrigeration system.
The applicant listed for this patent is Carrier Corporation. Invention is credited to John T. Steele.
Application Number | 20140331705 14/366317 |
Document ID | / |
Family ID | 47501470 |
Filed Date | 2014-11-13 |
United States Patent
Application |
20140331705 |
Kind Code |
A1 |
Steele; John T. |
November 13, 2014 |
Hydraulic Transport Refrigeration System
Abstract
A transport refrigeration system includes an engine, a hydraulic
pump driven by the engine, a supply line coupled to an output of
the pump, a supply control valve coupled to the supply line and a
refrigerant compressor coupled to the supply control valve through
a compressor supply line. The refrigerant compressor speed is
responsive to fluid flow in the compressor supply line.
Inventors: |
Steele; John T.; (Marcellus,
NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Carrier Corporation |
Farmington |
CT |
US |
|
|
Family ID: |
47501470 |
Appl. No.: |
14/366317 |
Filed: |
December 13, 2012 |
PCT Filed: |
December 13, 2012 |
PCT NO: |
PCT/US2012/069446 |
371 Date: |
June 18, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61577126 |
Dec 19, 2011 |
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Current U.S.
Class: |
62/228.1 |
Current CPC
Class: |
F25B 49/022 20130101;
B60P 3/20 20130101; B60H 1/3232 20130101; F25D 11/003 20130101;
B60H 1/00435 20130101 |
Class at
Publication: |
62/228.1 |
International
Class: |
F25D 11/00 20060101
F25D011/00; F25B 49/02 20060101 F25B049/02 |
Claims
1. A transport refrigeration system comprising: an engine; a
hydraulic pump driven by the engine; a supply line coupled to an
output of the pump; a supply control valve coupled to the supply
line; and a refrigerant compressor coupled to the supply control
valve through a compressor supply line, the refrigerant compressor
speed being responsive to fluid flow in the compressor supply
line.
2. The transport refrigeration system of claim 1 further
comprising: a high pressure accumulator coupled to the supply
control valve.
3. The transport refrigeration system of claim 2 wherein: the high
pressure accumulator is coupled to the compressor through the
supply control valve when the engine is at low speed.
4. The transport refrigeration system of claim 2 wherein: the high
pressure accumulator is coupled to the compressor through the
supply control valve upon start of the compressor.
5. The transport refrigeration system of claim 1 further
comprising: a return line coupled to an input of the pump; a return
control valve coupled to the return line; and a reservoir coupled
to the return control valve.
6. The transport refrigeration system of claim 1 further
comprising: a hydraulic motor coupled to the supply control
valve.
7. The transport refrigeration system of claim 6 wherein: the
hydraulic motor drives a fan.
8. The transport refrigeration system of claim 1 further
comprising: a controller for controlling the supply control valve
in response to input signals indicative of the operational status
of the transport refrigeration system.
9. The transport refrigeration system of claim 1 wherein: the
compressor is a hermetic compressor.
10. The transport refrigeration system of claim 1 wherein: the
compressor is a semi-hermetic compressor.
11. The transport refrigeration system of claim 10 wherein: the
compressor includes a hydraulic motor coupled to the compressor
supply line.
12. The transport refrigeration system of claim 11 wherein: the
compressor includes a casing, the casing having a chamber
containing the hydraulic motor, the casing housing a compressor
mechanism.
13. The transport refrigeration system of claim 12 further
comprising: an oil check valve providing a passage for oil from the
chamber to the compressor mechanism.
14. The transport refrigeration system of claim 11 further
comprising: a compressor control valve coupled to the compressor
supply line.
15. The transport refrigeration system of claim 14 wherein: the
compressor control valve is coupled to a compressor return line via
a bypass line.
16. The transport refrigeration system of claim 1 wherein: the
fluid in the compressor supply line is oil suitable for lubricating
the compressor.
17. The transport refrigeration system of claim 1 wherein: the
engine is a vehicle engine.
Description
BACKGROUND OF THE INVENTION
[0001] Embodiments of the invention relate generally to transport
refrigeration, and more particularly to a hydraulic transport
refrigeration system.
[0002] Existing transport refrigeration systems use an engine
(e.g., gas or diesel engine) to drive refrigeration system
components (e.g., compressor, fans). In order to improve efficiency
and reduce emissions, hybrid systems have been proposed to power
the transport refrigeration system. One hybrid system, described in
U.S. Patent Application Publication 20110000244 and assigned to
Carrier Corporation, uses an electrical hybrid power supply. While
existing designs are well suited for their intended purposes,
improvements in hybrid transport refrigeration systems would be
well received in the art.
BRIEF DESCRIPTION OF THE INVENTION
[0003] According to an exemplary embodiment of the present
invention, a transport refrigeration system includes an engine; a
hydraulic pump driven by the engine; a supply line coupled to an
output of the pump; a supply control valve coupled to the supply
line; and a refrigerant compressor coupled to the supply control
valve through a compressor supply line, the refrigerant compressor
speed being responsive to fluid flow in the compressor supply
line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The subject matter which is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features, and advantages of the invention are apparent from the
following detailed description taken in conjunction with the
accompanying drawings in which:
[0005] FIG. 1 depicts a hydraulic transport refrigeration system in
exemplary embodiments;
[0006] FIG. 2 depicts mounting of the transport refrigeration
system of FIG. 1 to a trailer; and
[0007] FIG. 3 depicts an exemplary semi-hermetic compressor for use
in the transport refrigeration system.
DETAILED DESCRIPTION OF THE INVENTION
[0008] FIG. 1 depicts a hydraulic powered transport refrigeration
system 100 in exemplary embodiments. The transport refrigeration
system 100 includes an engine 102 that drives a pump 104. Pump 104
provides hydraulic fluid to components of the transport
refrigeration system 100. Engine 102 may be a standalone engine
(gas or diesel) or may be the engine of the vehicle directly
driving pump 104 through, for example, a flywheel. Alternatively,
engine 102 may be a combination of a standalone engine and the
engine of the vehicle operating in conjunction. This allows the run
time of the standalone engine to be reduced, particularly during
periods when the vehicle engine has extra capacity (e.g., vehicle
idling).
[0009] A supply line 106 from an output of pump 104 provides fluid
to supply control valve 108. Supply control valve 108 is fluidly
coupled to a high-pressure accumulator 110, motor 112 and
compressor 114. Compressor 114 is coupled to supply control valve
108 by a compressor supply line 115. It is understood that multiple
supply control valves may be used, each coupled to an individual
system component. Supply line 106 may be coupled to a manifold,
with several supply control valves independently controlled by
controller 116 as described herein.
[0010] Motor 112 drives a fan shaft 113 for turning a fan (e.g.,
evaporator fan, condenser fan) in the transport refrigeration
system 100. Only one motor 112 is shown, but it is understood that
multiple motors 112 may be used, each for a respective system
component. Further, a single motor 112 may be coupled to multiple
fans, pumps, etc.
[0011] A controller 116 receives a number of input signals 118
indicative of the operational status of the transport refrigeration
system 100 and adjusts supply control valve 108 accordingly. Input
signals 118 may represent parameters such a pressure, temperature,
speed, etc. and are generated by sensors within transport
refrigeration system 100. Under periods of light load on the
transport refrigeration system, controller 116 diverts fluid to
high-pressure accumulator 110 to store fluid in a pressurized
state. When demand on the transport refrigeration system increases,
controller 116 can direct fluid from the high pressure accumulator
110 to motor 112 and compressor 114. This arrangement allows the
compressor 114 speed to be independent of engine 102 speed.
Controller 116 may be implemented using a general-purpose processor
executing software instructions to perform the steps described
herein. Alternatively, controller 116 may be implemented in
hardware, or with a combination of hardware and software.
[0012] Motor 112 and compressor 114 are fluidly coupled to a return
control valve 120. Compressor 114 is coupled to return control
valve 120 by a compressor return line 117. Return control valve 120
is coupled to an input of pump 104 via a return line 122 and is
coupled to a low-pressure reservoir 124. Controller 116 controls
the return control valve 120 in response to input signals 118
indicative of the operational status of the transport refrigeration
system 100. For example, under periods of light load on the
transport refrigeration system 100, return control valve 120
diverts excess fluid to reservoir 124. It is understood that
multiple return control valves may be used, each coupled to an
individual system component.
[0013] In the embodiment of FIG. 1, compressor 114 is a hermetic,
hydraulically driven compressor. Fluid from the supply control
valve 108 drives the compressor and is returned to pump 104 through
return control valve 120. In alternate designs, the pump 104 and
compressor 114 are encased together in a common housing preventing
loss of refrigerant that is typical in open drive systems.
[0014] FIG. 2 illustrates exemplary mounting of the transport
refrigeration system 100 to a trailer 150. As shown in FIG. 2, the
high-pressure accumulator 110 and the low pressure reservoir 124
are mounted to the underside of the trailer 150. The remaining
components of transport refrigeration system 100 may be mounted on
a front face of trailer 150. The evaporator coil and evaporator fan
(not show) may be positioned within trailer 150 as known in the
art.
[0015] The embodiment of FIG. 1 provides a hydraulic hybrid
transport refrigeration system 100 that improves efficiency. The
high-pressure accumulator 110 stores excess fluid pressure to drive
system components. By storing the fluid pressure, engine 102 need
not run, at least part of the time, when under light loads. Engine
power may also be supplemented during high load transients such as
during starts of the compressor 114, allowing a smaller engine 102
to be used. Additional savings would result as the engine could be
shut down under light load and the system ran off the accumulated
energy via the accumulator 110. Other savings may include reduced
total cost of ownership of the unit, reduced noise, reduced weight,
improved reliability of the compressor, design latitude for fan
designs, removal of belts typically used for fans, design latitude
for engine power/speed as well as component driven speed. In
addition, variable pitch pumps and motors can be used as well as
simple regulators to control speeds of fan, compressor, and other
devices.
[0016] FIG. 3 depicts an exemplary semi-hermetic compressor 200 for
use in the transport refrigeration system. Compressor 200 includes
a casing 202 housing elements of the compressor. A hydraulic
compressor motor 204 is positioned in a chamber 206 of casing 202.
Compressor supply line 115 is coupled to a compressor control valve
210. Compressor control valve 210 is controlled by controller 116
and controls the flow of fluid to compressor motor 204. Compressor
control valve 210 may divert some fluid to compressor return line
117 via a bypass line 212. This allows the compressor speed to be
controlled independently of engine speed. Fluid returned from the
compressor motor 204 is filtered at filter 214 and then provided to
compressor return line 117.
[0017] Refrigerant from suction port 216 is drawn into compression
mechanism 220 of compressor 200, where the refrigerant is
compressed and output through discharge port 222. The compressor of
FIG. 3 is a reciprocating compressor, but other types of
compressors may be used. An oil separator 224 may be positioned in
fluid communication with the discharge port 222. The oil separator
224 is fluidly coupled to the compressor return line 117 to return
oil to the return control valve 120.
[0018] Referring to FIG. 3, the shaft of the motor 204 is not
exposed to atmosphere, but rather to compressor internal pressure.
This provides for better compressor vacuum and better performance.
Also, any leaks in the seal around the shaft of motor 204 do not
result in a loss of refrigerant. The fluid in the compressor supply
line 115 that drives compressor motor 204 may be the same oil used
to lubricate the compressor. If motor 204 leaks fluid, the leaked
fluid can re-enter the compression mechanism 220 through an oil
check valve 226 positioned between chamber 206 and compression
mechanism 220.
[0019] While the invention has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the invention is not limited to such
disclosed embodiments. Rather, the invention can be modified to
incorporate any number of variations, alterations, substitutions or
equivalent arrangements not heretofore described, but which are
commensurate with the spirit and scope of the invention.
Additionally, while various embodiments of the invention have been
described, it is to be understood that aspects of the invention may
include only some of the described embodiments. Accordingly, the
invention is not to be seen as limited by the foregoing
description, but is only limited by the scope of the appended
claims.
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