Embodiments of the invention relate generally to transport refrigeration, and more particularly to a hydraulic transport refrigeration system.
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.
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.
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:
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.
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.
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.
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.
In the embodiment of
The embodiment of
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
Referring to
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.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2012/069446 | 12/13/2012 | WO | 00 | 6/18/2014 |
Number | Date | Country | |
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61577126 | Dec 2011 | US |