SG173543A1 - Temperature distribution improvement in refrigerated container - Google Patents
Temperature distribution improvement in refrigerated container Download PDFInfo
- Publication number
- SG173543A1 SG173543A1 SG2011056272A SG2011056272A SG173543A1 SG 173543 A1 SG173543 A1 SG 173543A1 SG 2011056272 A SG2011056272 A SG 2011056272A SG 2011056272 A SG2011056272 A SG 2011056272A SG 173543 A1 SG173543 A1 SG 173543A1
- Authority
- SG
- Singapore
- Prior art keywords
- fan
- container
- air
- refrigeration machine
- container box
- Prior art date
Links
- 238000009826 distribution Methods 0.000 title claims abstract description 15
- 238000005057 refrigeration Methods 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims description 5
- 230000000737 periodic effect Effects 0.000 claims description 2
- 238000009827 uniform distribution Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D11/00—Self-contained movable devices, e.g. domestic refrigerators
- F25D11/003—Transport containers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/0001—Control or safety arrangements for ventilation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F7/00—Ventilation
- F24F2007/005—Cyclic ventilation, e.g. alternating air supply volume or reversing flow direction
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
- F25D17/005—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces in cold rooms
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
- F25D2317/00—Details or arrangements for circulating cooling fluids; Details or arrangements for circulating gas, e.g. air, within refrigerated spaces, not provided for in other groups of this subclass
- F25D2317/06—Details or arrangements for circulating cooling fluids; Details or arrangements for circulating gas, e.g. air, within refrigerated spaces, not provided for in other groups of this subclass with forced air circulation
- F25D2317/068—Details or arrangements for circulating cooling fluids; Details or arrangements for circulating gas, e.g. air, within refrigerated spaces, not provided for in other groups of this subclass with forced air circulation characterised by the fans
- F25D2317/0684—Details or arrangements for circulating cooling fluids; Details or arrangements for circulating gas, e.g. air, within refrigerated spaces, not provided for in other groups of this subclass with forced air circulation characterised by the fans the fans allowing rotation in reverse direction
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Devices That Are Associated With Refrigeration Equipment (AREA)
- Cold Air Circulating Systems And Constructional Details In Refrigerators (AREA)
Abstract
The fan of a refrigeration machine operatively connected to a container box is operated in one direction during normal operation and is periodically operated in the opposite direction in order to reverse the direction of airflow to and from the container box so as to thereby promote a more uniform temperature distribution within the container box. A door is automatically closed when operating in the reverse direction so as to accelerate the airflow speed into the container box.
Description
Temperature Distribution Improvement in Refrigerated Container
[0001] This application claims priority to U.S. Provisional Patent
Application Serial No. 61/151,016 entitled “Temperature Distribution Improvement in Refrigerated Container,” filed on February 9, 2009. The content of this application is incorporated herein by reference in its entirety.
[0002] This invention relates generally to refrigerated containers and, more particularly, to a method and apparatus for obtaining a more uniform temperature distribution therein.
[0003] Refrigerated containers are used to transport perishable cargo that requires very tight temperature control. The industry standard today is to have the refrigeration machine mounted at one end of the container box. The air in the container box is drawn into the refrigeration machine by fans which then blow the warmer air through an evaporator coil, with the cooled air then passing back into the container box to cool the cargo. The common problem with this arrangement is that the cargo’s temperature tends to be higher towards the back door of the container and away from the refrigeration machine. The main reason is due to poor airflow distribution from the front to the back of the container box, with airflow being reduced significantly toward the back door. As a result, the temperature of the cargo is generally higher as it extends toward the rear door. The problem is exacerbated by the fact that the typical perishable cargo gives off heat of its own.
[0004] Briefly, in accordance with one aspect of the invention, the direction of the fan rotation is periodically reversed to thereby cause the direction of the airflow from and to the refrigerated container to be reversed to thereby improve the temperature distribution in the container box.
[0005] By another aspect of the invention, a plenum is provided at the top of the container box and is closed during the reverse operation in order to increase the airflow speed.
[0006] FIG. 1 is a perspective view of a refrigerated container with the present invention incorporated therein.
[0007] FIG. 2 is a schematic illustration thereof showing the airflow therein during normal operation.
[0008] FIG. 3 is a graphic illustration of the temperature distribution therein during normal operation.
[0009] FIG. 4 is a schematic illustration of the airflow pattern which results in a refrigerated container when operated in accordance with the present invention.
[0010] FIG. SA and 5B are perspective views of a door portion thereof during normal and reverse flow operation thereof.
[0011] A refrigerated container is shown generally at 11 as including a container box 12 having bottom and top sides 13 and 14 and front and rear ends 16 and 17. The container box 12 is designed to temporarily hold perishable cargo as shown at 18.
[0012] At the front end 16 of the container box 12, a refrigeration machine 19 is installed in such a manner as to fluidly communicate with the air in the container box 12 in order to cool that air for the purpose of refrigerating the cargo 18. The refrigeration machine 19 includes a standard refrigeration circuit comprising, in serial flow relationship, a compressor, a condenser, an expansion device and an evaporator. It is by the flow of the return air from the container box 12 and through the evaporator, that the air in the container box 12 is cooled.
Circulation of air through the evaporator and into and out of the container box 12 as shown in Fig. 1 is caused by operation of a fan 21 within the refrigeration machine 19.
[0013] As will be seen in Fig. 2, the fan 21 is located near a top portion 22 of the refrigeration machine 19 which, during normal operation, acts to draw the return air forwardly along a top portion 23 of the container box 12 and through an open door 24. The warm air is then blown through the evaporator coil 24 where the air is cooled, with the cooled air then being discharged from a lower portion 26 of the refrigeration machine 19. From there, the cooled air flows rearwardly through a bottom portion 27 of the container box 12 as shown by the arrows. The cooler air rises upwardly through a t-bar floor as indicated by the upwardly extending arrows.
[0014] The cooled air passes upwardly through the cargo 18 with heat being transferred thereto from the cargo 18. The warmer air then continues upwardly to enter the top portion 23 of the container box 12 to complete the cycle.
[0015] It should be recognized that as the cooled air travels rearwardly, it gradually becomes warmer such that when it reaches the rear end 17 it is at its higher temperature. Further, since the flow of air through the container box 12 relies on the momentum created by the fan 21 and the convection currents within the container box 12, the velocity of flow will be reduced as its extends toward the rear wall 17. For that reason, a substantial temperature gradient will exist both in the vertical direction and in the horizontal direction, within the container box 12. Since the cargo is exposed to this distribution of air for long periods of time such as days or even weeks, the temperature of the cargo 18 within the container box reflects a similar temperature distribution. This cargo temperature distribution is shown in
Iiig. 3. Here it will be seen that the cooler cargo will be in the lower left portion of the container box and the warmer cargo will be at the upper right portion thereof. In fact, at the top and rear of the container box 12 there is a hot spot that may well impact the quality of the cargo. That is, the perishable cargo temperature distribution in a container determines the shelf life of the cargo. Thus, the shelf life of the cargo will be variable as indicated by the temperature distribution in Fig. 3. It is thus desirable to eliminate the hot spots and promote a more uniform temperature distribution within the container box 12. This is accomplished by operation of the system as shown in Fig. 4.
[0016] Here, the fan 21 is caused to operate in reverse so as to draw air through the evaporator coil 14 rather than blow air therethrough. This causes an associated reversal of airflow through the container box 12 as shown by the arrows.
That is, the cooled air from the evaporator coil 24 passes upwardly through the fan 21 and into the top portion 22 of the refrigeration machine 19. From there it passes through the opening 30 and into the top portion 23 of the container box 12 to then flow rearwardly and downwardly as indicated by the arrows. The cooled air passes through the cargo 18 and then downwardly into the bottom portion 27 of the container box 12 before returning forwardly to the bottom portion 26 of the refrigeration machine 19 to complete the cycle. This reversal of flow causes mixing of the air within the container box 12 so as to thereby promote a more uniform distribution.
[0017] In order to increase the airflow speed, and thus the “throw”, during reverse flow operation, the door 25 is provided at the front end of the container top portion 23 as shown in igs. SA and 5B. That is, as shown in Fig. SA, during normal operation the return airflow causes the door 25 to open and allow the air to flow freely across the entire cross section of the top portion 23 as shown. However, in reverse flow operation, the flow of air will cause the door 25 to be moved to the closed position such that the opening 30 is of reduced cross section as shown in Fig. 5B. This will, in turn, cause the velocity of the airflow therethrough to increase, which will provide better “throw” and further promote mixing.
[0018] It is recognized that the blow-through operation of the fan 21 as shown in Fig. 2 is more efficient then the draw-through approach as shown in Fig. 4.
However, the time in which the fan 21 is operated in the reverse mode is relatively small compared with the time that it operates in the normal mode as shown in Fig. 2.
A typical time cycle of normal and periodic reverse operation is shown in Fig. 6.
[0019] While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.
Claims (6)
1. A method of operating a refrigerated container of the type having a refrigeration machine at one end of the container with the refrigeration machine having a fan for circulating warmer return air through an evaporator coil to be cooled and then to flow rearwardly to the container to cool its cargo, comprising the steps of: during normal operation, operating the fan in one direction so as to draw in return air at one end of the refrigeration machine and discharge it from the other end thereof; and periodically reversing the direction of the fan so as to draw in return air at the other end of the refrigeration machine and discharge it from the one end thereof; whereby the air in the refrigerated container is mixed so as to provide a more uniform temperature distribution throughout.
2. A method as set forth in claim 1 wherein said fan operates in a blow- through mode during normal operation and as a draw-through mode during periodic reverse operation.
3. A method as set forth in claim 1 wherein said refrigeration machine one end is near the top thereof and the other end is near a bottom end thereof.
4. A method as set forth in claim 1 and including the steps of providing a door near said one end and opening said door when said fan is operating in said one direction and closing it when operating in said reverse direction.
5. A refrigeration machine for use with a container of a type for holding cargo to be refrigerated, comprising: an evaporator coil; a fan for causing warm air to be drawn in from one portion of the container box, to pass through the evaporator coil to be cooled, and then flow outwardly from the refrigeration machine to another portion of the container box; and a control for selectively operating the fan in one direction so as to draw in air from said container box one portion and return cooled air to said container box other portion and, periodically, reversing the direction of the fan such that the air is drawn in from said container box other portion and the cooled air is returned to said container box one portion.
6. A refrigeration machine as set forth in claim 5 and including a door near said box one portion and so as to be automatically opened when said fan is operated in said one direction and closed when said fan is operating in said reverse direction.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15101609P | 2009-02-09 | 2009-02-09 | |
PCT/US2010/023196 WO2010091181A1 (en) | 2009-02-09 | 2010-02-04 | Temperature distribution improvement in refrigerated container |
Publications (1)
Publication Number | Publication Date |
---|---|
SG173543A1 true SG173543A1 (en) | 2011-09-29 |
Family
ID=42542381
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
SG2011056272A SG173543A1 (en) | 2009-02-09 | 2010-02-04 | Temperature distribution improvement in refrigerated container |
Country Status (6)
Country | Link |
---|---|
US (1) | US20110283719A1 (en) |
EP (1) | EP2394111B1 (en) |
CN (1) | CN102308165B (en) |
DK (1) | DK2394111T3 (en) |
SG (1) | SG173543A1 (en) |
WO (1) | WO2010091181A1 (en) |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100258642A1 (en) * | 2008-09-22 | 2010-10-14 | Newcomer Douglas A | Enviromental control systems and methods of configuring environmental control systems |
WO2012017301A1 (en) * | 2010-08-04 | 2012-02-09 | Stellenbosch University | Refrigeration transport container |
DE102011075946A1 (en) * | 2011-05-17 | 2012-11-22 | BSH Bosch und Siemens Hausgeräte GmbH | Refrigerating appliance e.g. household refrigerating appliance has control circuit, temperature sensor and timer that are arranged within storage chamber for reversing air circulation direction at operating phase of evaporator |
CN103964088B (en) * | 2013-01-28 | 2017-10-31 | 中国国际海运集装箱(集团)股份有限公司 | Ventilation unit and the frozen products insulated container with the ventilation unit |
GB2552084B (en) * | 2014-01-29 | 2018-08-01 | Illinois Tool Works | A locker system |
CN104879977A (en) * | 2014-02-28 | 2015-09-02 | 株式会社电装 | Apparatus for adjusting temperature and storing |
CN208720605U (en) | 2015-10-09 | 2019-04-09 | Ite株式会社 | System for maintaining refrigerated storage temperature in cold-storage apparatus |
CN105758164A (en) * | 2016-04-29 | 2016-07-13 | 谢东波 | Balanced circulation system for confined space |
CN107401874A (en) * | 2017-09-13 | 2017-11-28 | 珠海格力电器股份有限公司 | Container and its air blowing control method |
MY201750A (en) * | 2018-05-31 | 2024-03-15 | Hitachi Johnson Controls Air Conditioning Inc | Air conditioner |
AR117003A1 (en) * | 2019-11-06 | 2021-06-30 | Juan Domingo Lombard | METHOD FOR REDUCING THE CHILLING DAMAGE OF A CHANNEL |
DK180928B1 (en) * | 2020-03-05 | 2022-06-29 | Maersk Container Ind A/S | Transport unit and method of controlling an atmosphere therein |
CN111895713A (en) * | 2020-06-24 | 2020-11-06 | 卧龙电气驱动集团股份有限公司 | Uniform air outlet device applied to refrigerator air duct and control method |
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FR2498429A1 (en) * | 1981-01-27 | 1982-07-30 | Carboxyque Francaise | IMPROVED REFRIGERATION CHAMBER |
DE3111877A1 (en) * | 1981-03-26 | 1982-10-14 | Kunststoff- und Kältetechnik Großkopf GmbH, 4300 Essen | "REFRIGERATED VEHICLE WITH TWO CHAMBERS" |
US4689533A (en) * | 1985-10-25 | 1987-08-25 | Yang Tai Her | Controlled fan |
GB8706574D0 (en) * | 1987-03-19 | 1987-04-23 | Yang Tai Her | Circulating fan |
US4736597A (en) * | 1987-04-08 | 1988-04-12 | Thermo King Corporation | Transport refrigeration system |
US4936104A (en) * | 1988-07-21 | 1990-06-26 | Hicke Gerald E | Air conditioning method and apparatus for refrigerated vehicles |
US4979431A (en) * | 1988-11-08 | 1990-12-25 | Mitsui O. S. K. Lines, Ltd. | Gaseous flow construction of box member for refrigerated transportion and box member for refrigerated transportation using the same |
US5319941A (en) * | 1992-09-22 | 1994-06-14 | Trans-Pak, Inc. | System and method for storing perishable products in a refrigerated cargo bay |
US5789007A (en) * | 1996-04-24 | 1998-08-04 | Cool Care, Ltd. | Method and apparatus for controlled ripening of fresh produce |
US5809798A (en) * | 1996-09-26 | 1998-09-22 | Cornerstone Technologies, Ltd. | Refrigerated container with controlled air distribution |
US5830057A (en) * | 1996-10-17 | 1998-11-03 | Coldwall Technologies Limited | Integrated temperature-controlled container |
US5816053A (en) * | 1997-05-08 | 1998-10-06 | Cloverdale Foods Company | Apparatus and methods for cooling and tempering processed food products |
US6405543B2 (en) * | 1997-05-16 | 2002-06-18 | Work Smart Energy Enterprises Inc. | High-efficiency air-conditioning system with high-volume air distribution |
JPH10325668A (en) * | 1997-05-28 | 1998-12-08 | Daikin Ind Ltd | Freezing container |
US5867994A (en) * | 1997-09-19 | 1999-02-09 | Kopko; William L. | Dual-service evaporator system for refrigerators |
US5916253A (en) * | 1998-05-04 | 1999-06-29 | Carrier Corporation | Compact trailer refrigeration unit |
US6574970B2 (en) * | 2000-02-18 | 2003-06-10 | Toc Technology, Llc | Computer room air flow method and apparatus |
US6758057B2 (en) * | 2002-07-30 | 2004-07-06 | Vince, Ii Gerard C. | Bimodal refrigeration system and method |
JP2005257095A (en) * | 2004-03-09 | 2005-09-22 | Isuzu Motors Ltd | Vehicle with gas cooler |
CN101198833A (en) * | 2005-05-25 | 2008-06-11 | 利勃海尔-家用电器奥克森豪森有限责任公司 | Cooling and/or freezing device |
US7516624B2 (en) * | 2005-06-01 | 2009-04-14 | Weeth Frederic R | Cooling room |
EP2013556A4 (en) * | 2006-05-01 | 2012-08-15 | Carrier Corp | Indoor air quality improvement by re-evaporation control |
-
2010
- 2010-02-04 SG SG2011056272A patent/SG173543A1/en unknown
- 2010-02-04 WO PCT/US2010/023196 patent/WO2010091181A1/en active Application Filing
- 2010-02-04 DK DK10739123.7T patent/DK2394111T3/en active
- 2010-02-04 US US13/146,104 patent/US20110283719A1/en not_active Abandoned
- 2010-02-04 CN CN201080007100.7A patent/CN102308165B/en not_active Expired - Fee Related
- 2010-02-04 EP EP10739123.7A patent/EP2394111B1/en not_active Not-in-force
Also Published As
Publication number | Publication date |
---|---|
DK2394111T3 (en) | 2017-01-23 |
CN102308165B (en) | 2014-06-18 |
WO2010091181A1 (en) | 2010-08-12 |
EP2394111A1 (en) | 2011-12-14 |
CN102308165A (en) | 2012-01-04 |
EP2394111A4 (en) | 2015-08-26 |
US20110283719A1 (en) | 2011-11-24 |
EP2394111B1 (en) | 2016-10-12 |
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