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
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
  • F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
• • 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
  • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
  • F25B1/00—Compression machines, plants or systems with non-reversible cycle

Definitions

• the subject matter disclosed herein relates to a system to perform a vapor compression refrigeration cycle using water as the refrigerant.
• Vapor-compression refrigeration is of the many refrigeration cycles available for use. It has been and is the most widely used method for air-conditioning of large public buildings, offices, private residences, hotels, hospitals, theaters, restaurants and automobiles. It is also used in domestic and commercial refrigerators, large-scale warehouses for chilled or frozen storage of foods and meats, refrigerated trucks and railroad cars, and a host of other commercial and industrial services, such as oil refineries, petrochemical and chemical processing plants, and natural gas processing plants.
• Refrigeration may be defined as a lowering of a temperature of an enclosed space by the removal of heat from that space and transferring the heat elsewhere.
• a typical vapor- compression refrigeration system uses a circulating liquid refrigerant as the medium that absorbs and removes heat from the space to be cooled and subsequently rejects that heat elsewhere. All such systems have four components: a compressor, a condenser, a fluid expansion device (typically a throttling valve but sometimes a work recovery expansion device) and an evaporator. Circulating refrigerant enters the compressor in the thermodynamic state known as a saturated or a slightly superheated vapor and is compressed to a higher pressure, resulting in a higher temperature as well.
• the hot, compressed vapor is then in the thermodynamic state known as a superheated vapor and it is at a temperature and pressure at which it can be condensed with typically available cooling water or cooling air. That hot vapor is routed through a condenser where it is cooled and condensed into a liquid by flowing through a coil or tubes with cool water or cool air flowing across the coil or tubes. This is where the circulating refrigerant rejects heat from the system and the rejected heat is carried away by either the water or the air (whichever may be the case).
• the condensed liquid refrigerant which is now in the thermodynamic state known as a saturated or a slightly sub-cooled liquid, is next routed through an expansion device where it undergoes an abrupt reduction in pressure. That pressure reduction results in the adiabatic flash evaporation of a part of the liquid refrigerant.
• the auto-refrigeration effect of the adiabatic flash evaporation lowers the temperature of the liquid and vapor refrigerant mixture to where it is colder than the temperature of the enclosed space to be refrigerated.
• the cold mixture is then routed through the coil or tubes in the evaporator.
• a fan circulates the warm air in the enclosed space across the coil or tubes carrying the cold refrigerant liquid and vapor mixture.
• That warm air evaporates the liquid part of the cold refrigerant mixture.
• the circulating air is cooled and, thus, lowers the temperature of the enclosed space to the desired temperature.
• the evaporator is where the circulating refrigerant absorbs and removes heat from the enclosed space, which is subsequently rejected in the condenser and transferred elsewhere by the water or air used in the condenser.
• the refrigerant vapor from the evaporator is again a saturated or slightly superheated vapor and is routed back into the compressor.
• a system to perform a vapor compression refrigeration cycle using water as the refrigerant includes an evaporator to output water vapor having a water vapor temperature of a first temperature and a water vapor pressure of a first pressure, a condenser to output liquid water at a second temperature, which is higher than the first temperature, and a second pressure, which is higher than the first pressure and a compressor, operably disposed downstream from the evaporator and upstream from the condenser, to compress the water vapor to thereby increase the water vapor temperature from the first temperature and to thereby increase the water vapor pressure from the first pressure by at least a 7:1 ratio.
• a system to perform a vapor compression refrigeration cycle using water as the refrigerant includes an evaporator to output water vapor having a water vapor temperature of a first temperature and a water vapor pressure of a first pressure, a condenser to output liquid water at a second temperature, which is higher than the first temperature, and a second pressure, which is higher than the first pressure and a supersonic compressor, operably disposed downstream from the evaporator and upstream from the condenser, to supersonically compress the water vapor to thereby increase the water vapor temperature from the first temperature and to thereby increase the water vapor pressure from the first pressure by at least a 7:1 ratio.
• a system to perform a vapor compression refrigeration cycle using water as the refrigerant includes an evaporator to vaporize liquid water to produce water vapor and to output the water vapor having a water vapor temperature of a first temperature and a water vapor pressure of a first pressure, a condenser to output liquid water at a second temperature, which is higher than the first temperature, and a second pressure, which is higher than the first pressure and a supersonic compressor assembly having a first stage centrifugal compressor and a second stage supersonic compressor, operably disposed downstream from the evaporator and upstream from the condenser, to supersonically compress the water vapor to thereby increase the water vapor temperature from the first temperature and to thereby increase the water vapor pressure from the first pressure by at least a 7:1 ratio.
• FIG. 1 illustrates a system to perform a refrigeration cycle
• FIG. 2 is a flow diagram illustrating a method of operating the system of FIG. 1.
• the proposed invention adapts the operating principles of the supersonic aircraft inlet to a rotary supersonic compressor to enable the use of water or other low density refrigerants in vapor-compression refrigeration.
• a system 10 to perform a vapor compression refrigeration cycle using water as the refrigerant includes a compressor 20, a condenser 30, a fluid expansion device 40 (typically a throttling valve but sometimes a work recovery expansion device) and an evaporator 50.
• a fluid expansion device 40 typically a throttling valve but sometimes a work recovery expansion device
• evaporator 50 typically a throttling valve but sometimes a work recovery expansion device
• circulating water vapor enters the compressor 20 in the thermodynamic state known as a saturated or a slightly superheated vapor and is compressed from a first temperature and a first pressure to a second, higher pressure and a second, higher temperature.
• the hot, compressed water vapor is then in the thermodynamic state known as a superheated vapor and it is at a greater temperature and pressure relative to, for example, ambient conditions, such that it can be condensed with typically available cooling water or cooling air.
• That hot water vapor is routed through the condenser 30 where it is cooled and condensed into a liquid by flowing through a coil or tubes with cool water or cool air flowing across the coil or tubes.
• the condensed liquid water which is now in the thermodynamic state known as a saturated or a slightly sub-cooled liquid, is next routed through the expansion device 40, which is operably disposed downstream from the condenser 30 and upstream from the evaporator 50, where it undergoes an abrupt reduction in pressure. That pressure reduction results in the adiabatic flash evaporation of a part of the water.
• the auto-refrigeration effect of the adiabatic flash evaporation lowers the temperature of the liquid water to where it is colder than the temperature of the enclosed space to be refrigerated.
• the cold water is then routed through the coil or tubes in the evaporator 50.
• a fan 55 circulates the warm air in the enclosed space to be cooled across the coil or tubes carrying the cold water. That warm air evaporates the liquid water and, at the same time, the circulating air is cooled. Thus, the temperature of the enclosed space is lowered to the desired temperature.
• the evaporator 50 is representative of a location where the circulating water absorbs and removes heat from the enclosed space. To complete the refrigeration cycle, the water vapor from the evaporator 50 is again a saturated or a slightly superheated vapor and is routed back into the compressor 20.
• the compressor 20 may have only a single supersonic compression stage or, as an alternative, may include a supersonic compressor assembly 21 having a first stage centrifugal compressor 22 and a second stage supersonic compressor 23, where the two stages may be counter rotating. As shown in FIG. 1, the supersonic compressor assembly 21 is operably disposed downstream from the evaporator 50 and upstream from the condenser 30. In this configuration, the system 10 may have an isentropic compression efficiency of about 90% with a reduced number of stages as compared to conventional compressors.
• the supersonic compressor assembly 21 supersonically compresses the water vapor to thereby increase the water vapor temperature from the first temperature and to thereby increase the water vapor pressure from the first pressure by at least a 7:1 ratio or, in some cases, at least an 8:1 ratio and, in still further cases, at least a 10:1 ratio.
• the first temperature may be about 45 degrees Fahrenheit and the first pressure may be about 0.09 pounds per square inch on the low side to 0.1-0.2 pounds per square inch on the high side.
• the water vapor temperature is increased from the first temperature to about 100 degrees Fahrenheit and the water vapor pressure is increased from the first pressure to about 0.1-0.2 pounds per square inch on the low side and 1-2 pounds per square inch on the high side.
• the first temperature may be about 45 degrees Fahrenheit and the first pressure may be about 0.15 pounds per square inch.
• the water vapor temperature is increased from the first temperature to about 100 degrees Fahrenheit or somewhat higher and the water vapor pressure is increased from the first pressure to about 1.0 - 1.5 pounds per square inch.
• the system 10 can accommodate a relatively high volumetric flow rate and a high compression ratio as compared to conventional refrigeration system compressors.
• a compressor inlet specific volume may be 0.953 ft /lbm.
• the same sized system using water as a refrigerant and supersonic compression may have a compressor inlet specific volume of about 2,400- 2,500 ft 3 /lbm or approximately 2,444 ft 3 /lbm.
• water may be substituted for with other similarly low density refrigerants that have no or limited global warming impact.
• the method includes operably disposing the compressor 20 downstream from the evaporator 50 and upstream from the condenser 30 (200), providing water vapor output from the evaporator 50 to the compressor 20, the water vapor having a water vapor temperature of a first temperature and a water vapor pressure of a first pressure (201), compressing the water vapor at the compressor 20 to thereby increase the water vapor temperature from the first temperature and to thereby increase the water vapor pressure from the first pressure by at least a 7:1 ratio (202) and providing the water vapor from the compressor 20 to the condenser 30 (203).
• the compressor 20 may be provided as a supersonic compressor assembly 21 that includes a first stage centrifugal compressor 22 and a second stage supersonic compressor 23.
• the compressing is achieved by the supersonic compressor assembly 21 supersonically compressing the water vapor.
• a specific volume of the water vapor at an inlet of the supersonic compressor assembly 21 is about 2,400-2,500 ft /lbm and the water vapor pressure may be increased by at least a 7:1 ratio, an 8:1 ratio or a 10:1 ratio.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Heat-Pump Type And Storage Water Heaters (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Other Air-Conditioning Systems (AREA)

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• 2012
  • 2012-01-23 WO PCT/US2012/022180 patent/WO2012102992A2/fr not_active Ceased
  • 2012-01-23 RU RU2013135652/06A patent/RU2573726C2/ru not_active IP Right Cessation
  • 2012-01-23 EP EP12702694.6A patent/EP2668455B1/fr active Active
  • 2012-01-23 CN CN201280006588.0A patent/CN103339449B/zh active Active
  • 2012-01-23 US US13/982,112 patent/US20130305775A1/en not_active Abandoned

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