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  Defrost refrigeration systemUSPTO Application #: 20060130494Title: Defrost refrigeration system Abstract: A defrost refrigeration system of the type having a main refrigeration circuit comprising a first line extending from the compression stage to the evaporator stage and adapted to receive a portion of refrigerant in a high-pressure gas state. A valve system stops a flow of the refrigerant in a low-pressure liquid state to an evaporator of the evaporator stage and for conveying a flow of the refrigerant in the high-pressure gas state from the first line to release heat to defrost the at least one evaporator. A second line conveys the refrigerant having released heat directly to the condensing stage. (end of abstract) Agent: Ogilvy Renault LLP - Montreal, QC, CA Inventor: Serge Dube USPTO Applicaton #: 20060130494 - Class: 062081000 (USPTO) Related Patent Categories: Refrigeration, Processes, Defrosting Or Frost Inhibiting, By Utilizing Working Fluid Of Refrigeration Producer The Patent Description & Claims data below is from USPTO Patent Application 20060130494. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD [0001] The present invention generally relates to refrigeration systems and, more particularly, to a refrigeration system having a defrost cycle in parallel to the refrigeration cycle, with refrigerant of the refrigeration system being circulated in the evaporators to perform the defrost cycle. BACKGROUND ART [0002] Energy costs are an increasing concern for industries operating refrigeration systems, such as the food retailing industry. Due to the increasing costs of energy, refrigeration systems are evolving to provide refrigeration system solutions that optimize the use of energy. [0003] Defrost cycles are common place in refrigeration systems, and are used to remove frost build-ups on evaporators. Frost build-ups typically result from the relatively high humidity content of the air to which the evaporators are exposed. [0004] One type of defrost cycle consists in circulating hot refrigerant in the evaporators, such that the hot refrigerant releases heat to the frost build-up, which melts away. Such defrost cycles are operated in relatively short time spans, so as not to expose the foodstuff being refrigerated to unsuitable temperatures. [0005] The overall installation costs of the defrost loops (e.g., piping, valves, controls) are being compared to the energy consumption of operating such defrost loops. It would therefore be desirable to optimize the consumption of energy for defrost cycles of refrigeration systems. SUMMARY OF INVENTION [0006] Therefore, it is a feature of the present invention to provide a novel defrost circuit for a refrigeration system. [0007] It is a further feature of the present invention to provide a defrost circuit optimizing energy consumption. [0008] It is a still further feature of the present invention to provide a novel method for defrosting evaporators of a refrigeration system. [0009] Therefore, in accordance with the present invention there is provided a defrost refrigeration system of the type having a main refrigeration circuit, wherein a refrigerant goes through at least a compression stage, wherein said refrigerant is compressed to a high-pressure gas state to then reach a condensing stage, wherein said refrigerant in said high-pressure gas state is condensed at least partially to a high-pressure liquid state to then reach an expansion stage, wherein said refrigerant in said high-pressure liquid state is expanded to a first low-pressure liquid state to then reach an evaporator stage, wherein said refrigerant in said first low-pressure liquid state is evaporated at least partially to a first low-pressure gas state by absorbing heat, to then return to said compression stage, said defrost refrigeration system comprising: a first line extending from the compression stage to the evaporator stage and adapted to receive a portion of said refrigerant in said high-pressure gas state; a valve system for stopping a flow of said refrigerant in said first low-pressure liquid state to at least one evaporator of the evaporator stage and for conveying a flow of said refrigerant in said high-pressure gas state from the first line to release heat to defrost the at least one evaporator; and a second line to convey said refrigerant having released heat directly to the condensing stage. [0010] Further in accordance with the present invention, there is provided a method for defrosting evaporators in a refrigeration system operating a refrigeration cycle, comprising the steps of: providing a first line extending from a compression stage of the refrigeration system to an evaporation stage of the refrigeration system, a second line extending from the evaporation stage of the refrigeration system directly to a condensing stage of the refrigeration system; stopping a flow of cooling refrigerant to at least one evaporator; conveying hot gas refrigerant from the compressing stage to the at least one evaporator through said first line so as to defrost the at least one evaporator; and conveying the hot gas refrigerant from the at evaporator directly to the condensing stage by the second line so as to return the refrigerant to the refrigeration cycle. BRIEF DESCRIPTION OF DRAWINGS [0011] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which: [0012] FIG. 1 is a schematic view of a defrost refrigeration system in accordance with a first embodiment of the present invention; [0013] FIG. 2 is a schematic view of a defrost refrigeration system in accordance with a second embodiment of the present invention; and [0014] FIG. 3 is a schematic plan view of the defrost refrigeration system of FIG. 1. DESCRIPTION OF PREFERRED EMBODIMENTS [0015] Referring to the drawings, and more particularly to FIG. 1, a refrigeration system in accordance with the present invention is generally shown at 10. The refrigeration system 10 comprises the stages found on typical refrigeration systems, such as the compression stage 12, the condensation stage 14, the expansion stage 16, and the evaporation stage 18. [0016] Refrigerant circulates from one stage to another in a refrigeration cycle. The refrigerant is compressed to a high pressure gas state in the compression stage 12. The compression stage 12 is connected to the condensation stage 14 by line 13 (i.e., a hot gas line). The refrigerant then releases heat in the condensation stage 14, to reach a high pressure liquid state. The refrigerant is expanded in the expansion stage 16 to reach the evaporation stage 18 in a low pressure liquid/gas state. In the evaporators of the evaporation stage 18, the refrigerant absorbs heat to reach a low pressure gas state, to then reach the compression stage 12 and complete the refrigeration cycle. [0017] For the purposes of illustrating the defrost system of the present invention, the evaporation stage 18 is shown having evaporators 20A and 20B. Sub-lines 21A and 21B of line 21 relate the expansion stage 16 to the evaporators 20A and 20B, respectively. Sub-lines 22A and 22B of line 22 relate the evaporators 20A and 20B, respectively, to the compression stage 12. [0018] In known refrigeration systems having defrost loops, hot refrigerant is directed to one or more of the evaporators of the evaporation stage, so as to release heat to melt the frost build-up on the evaporators. In some systems, the lines extending between the evaporators of the evaporation stage and the compressors of the compression stage are then used, with appropriate valves, to direct the defrosting refrigerant exiting from the evaporators to a subsequent portion of the refrigeration system, such as a suction header, a suction accumulator, a pressure regulator device, or the like. [0019] The suction lines relating the evaporators of the evaporation stage to the compression stage in multi-evaporator refrigeration systems are known to have relatively large diameters, so as to prevent suction pressure loss between the evaporation stage and the compression stage. Continue reading... Full patent description for Defrost refrigeration system Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Defrost refrigeration system patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Defrost refrigeration system or other areas of interest. ### Previous Patent Application: Nmr spectrometer with common refrigerator for cooling an nmr probe head and cryostat Next Patent Application: System and method of refrigeration Industry Class: Refrigeration ### FreshPatents.com Support Thank you for viewing the Defrost refrigeration system patent info. 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