Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04F—PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
  • F04F5/00—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow
  • F04F5/44—Component parts, details, or accessories not provided for in, or of interest apart from, groups F04F5/02 - F04F5/42
  • F04F5/46—Arrangements of nozzles
  • F04F5/461—Adjustable nozzles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04F—PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
  • F04F5/00—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow
  • F04F5/14—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow the inducing fluid being elastic fluid
  • F04F5/16—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow the inducing fluid being elastic fluid displacing elastic fluids
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04F—PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
  • F04F5/00—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow
  • F04F5/44—Component parts, details, or accessories not provided for in, or of interest apart from, groups F04F5/02 - F04F5/42
  • F04F5/46—Arrangements of nozzles
  • F04F5/463—Arrangements of nozzles with provisions for mixing
• • 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
  • F25B1/06—Compression machines, plants or systems with non-reversible cycle with compressor of jet type, e.g. using liquid under pressure
  • F25B1/08—Compression machines, plants or systems with non-reversible cycle with compressor of jet type, e.g. using liquid under pressure using vapour under pressure

Definitions

• the present invention relates to an ejector, such as an ejector for a solar cooling system.
• the electrical energy is often generated using power stations that burn fossil fuel and consequently emit undesirable pollutants and greenhouse gases.
• Photovoltaic solar panels may be used to convert sunlight into electrical energy that can be used to operate an electric motor that drives a gas compressor of a cooling system. This may reduce the need for fossil fuels, but the efficiency is relatively low and the capital cost is relatively high.
• Cooling systems that are operated using thermal solar energy and have ejectors instead of corresponding
• the present invention provides in a first aspect an ejector comprising:
• a fluid nozzle positioned in the housing portion and coupled to the first fluid inlet, the fluid nozzle being arranged such that a first fluid that has a fluid inlet pressure PI and is received by the first fluid inlet has a fluid nozzle exit pressure after passing through the fluid nozzle, the fluid nozzle exit pressure being lower than PI;
• a mixing region arranged such that the first fluid when passing through the mixing region draws a second fluid from the second fluid inlet such that the first and second fluids mix;
• the ejector is arranged such that a position of an outlet of the fluid nozzle relative to the mixing region is adjusted dependent on PI and/or a pressure of the mixed first and second fluids.
• the ejector may be arranged such that a position of the outlet of the fluid nozzle relative to the mixing region is self-adjusted dependent on PI and/or a pressure of the mixed first and second fluids.
• the ejector may comprise a passive structure that is arranged for self-adjusting of the position of the outlet of the fluid nozzle.
• the ejector may also comprise an actuator that is arranged to adjust a position of the outlet of the fluid nozzle dependent on PI and/or a pressure of the mixed first and second fluids.
• the ejector is arranged such that the first fluid has a second pressure P2 after passing through the fluid nozzle, P2 being lower than PI, and the mixture of the first and second fluid exits the ejector with a third pressure P3;
• the ejector is arranged such that the position of the outlet of the fluid nozzle relative to the mixing region is adjusted dependent on PI, P2 and/or P3.
• the ejector typically comprises an ejector diffuser having an interior portion with a cross-sectional area that increases in diameter in a direction towards the fluid outlet and is arranged such that the mixture of the first and second fluid exits the ejector through the fluid outlet with the third pressure P3.
• the ejector may comprise a converging region that is provided in addition to the mixing region and that is positioned such that the mixed first and second fluids converge before exiting the ejector, the converging region having a cross-sectional area that reduces in diameter in a direction towards the outlet of the ejector.
• the mixing region may be provided in the form of a converging region and may be arranged such that the first and second fluids converge during or after mixing and before exiting the ejector, the converging region having a cross-sectional area that reduces in diameter in a direction towards the outlet of the ejector.
• the ejector is typically arranged such that the outlet of the fluid nozzle, and typically the entire fluid nozzle, moves towards or away from the converging region if the pressure of the mixed first and second fluids (such as P2 or P3) changes relative to another pressure within the ejector .
• the ejector is typically arranged such that the outlet of the fluid nozzle, and typically the entire fluid nozzle, moves away from the converging region if P2 increases and towards or into the converging region of P3 increases .
• Embodiments of the present invention have significant practical advantages.
• An ideal position of the fluid nozzle is dependent on PI, P2 and/or P3. Consequently, the adjusting of the relative position of the fluid nozzle may increase the ejector's efficiency.
• a length by which the relative position of the ejector is adjusted is largely proportional to a change in pressure of the mixed first and second fluids (such as P2 or P3) relative to another pressure in the ejector .
• the ejector may comprise a conduit that is arranged such that a portion at or near the fluid nozzle of the ejector has a pressure that is proportional to, or substantially equals, a pressure of the mixed first and second fluids and wherein the ejector is arranged such that that portion is isolated form unmixed first and second fluids.
• the ejector comprises a conduit that is arranged such that a portion at or near the fluid nozzle of the ejector has a pressure that is proportional to, or substantially equals, the pressure P2 or P3 and wherein the ejector is arranged such that that portion is isolated form unmixed first and second fluids.
• the ejector may comprise a diaphragm.
• the diaphragm may seal at least a portion around the fluid nozzle.
• the ejector may be arranged such that the fluid nozzle or a portion thereof moves until the diaphragm and/or another portion of the ejector provides a sufficient reaction force for locating the fluid nozzle in an adjusted position .
• the diaphragm may surround the fluid nozzle or may alternatively only be positioned around a portion of the fluid nozzle.
• the diaphragm typically comprises a suitable polymeric material, such as a rubber material.
• the ejector may comprise a moveable wall portion, such as a moveable wall portion that is rigid and may be coupled to a spring.
• the moveable wall portion may be coupled directly or indirectly to the fluid nozzle such that the fluid nozzle or a portion thereof moves with the moveable wall portion until the spring provides a
• the conduit may be arranged such that a side portion of the diaphragm or the moveable wall portion is exposed to a pressure that is proportional to, or approximately equals, the pressure of the mixed first and second fluids, wherein the ejector may be arranged such that an increase in the pressure of the mixed first and second fluids relative to another pressure within the ejector results in a movement of the nozzle or portion thereof relative to the mixing region of the ejector.
• the ejector typically is arranged such that an increase in the pressure of the mixed first and second fluids relative to P3 results in a movement of the nozzle or portion thereof away from the mixing region of the ejector.
• the ejector typically is arranged such that an decrease in the pressure of the mixed first and second fluids relative to P3 results in a movement of the nozzle or portion thereof into or towards the mixing region of the ejector.
• the present invention also provides a method of operating an ejector, the method comprising:
• the step of adjusting a position of an outlet of the fluid nozzle relative to the mixing region of the ejector may comprise self-adjusting a position of an outlet of the fluid nozzle.
• the mixing region may comprise, or may be provided in the form of, the converging region.
• Figure 1 shows a schematic cross-sectional representation of an ejector in accordance with an embodiment of the present invention
• Figures 2 and 3 show perspective side views of the ejector in accordance with an embodiment of the present invention
• Figure 4 is a flow chart illustrating a method of
• FIG. 5 illustrates the operation of a heat pump
• an ejector 100 in accordance with an embodiment of the present invention is now described.
• the ejector 100 may be operated to drive a heat pump of a refrigeration cycle, in which case the ejector 100 may be used in place of a conventional electric compressor, which will be described in more details further below with reference to Figure 5.
• the ejector 100 has a body 102 that is generally
• the body 102 comprises a nozzle housing 104 and a diffuser portion 106.
• a fluid nozzle 108 is
• the body 102 also comprises a mixing region that is provided in the form of a converging region 110 and has a cross-sectional area that reduces in a direction away from the nozzle 108 and along an axis of the ejector 100.
• the diffuser portion 106 further comprises a diverging region 118 that has a cross- sectional area that increases in a direction away from the nozzle 108 and along an axis of the ejector 100.
• the ejector 100 has a first inlet 114 for receiving a first fluid such as a refrigerant. Further, the ejector 100 has a second inlet 116 for receiving a second fluid that may also be a refrigerant.
• first and second fluids may be of various different types.
• the first and/or the second fluids may alternatively be air, water, water vapour or refrigerant vapour or any other suitable fluid.
• the first fluid 114 has a pressure PI before penetrating through the nozzle 108.
• the nozzle 108 has a diverging region 109 through which the first fluid exits the nozzle 108 and that results in an expansion of the first fluid, which further expands a converging region 110 in which it has a reduced pressure P2 (and the velocity of the first fluid is increased) .
• the pressure P2 is sufficiently low such that the second fluid is drawn through the second inlet
• the mixture of the first and second fluids penetrates through the converging region 110, a cylindrical region 112, the diffusing region 118 and then exits the ejector 100 with a pressure P3.
• the ejector 100 functions as a pump or compressor that increases the pressure of the second fluid.
• the efficiency with which the ejector 100 pumps the second fluid depends on various operation parameters including the differences between the pressures PI, P2 and P3 for a given design of the ejector 100. For example, for larger P3 relative to PI, the nozzle 108 should be positioned further within the converging region 110 than for smaller P3.
• the nozzle 108 is movable along an axis of the ejector 100 such that positioning of the nozzle 108 as a function of P3, P2 and PI is possible.
• the nozzle 108 has in this embodiment a holder 121 in which the nozzle 108 slides along the axis of the ejector 100.
• the ejector 100 also comprises a diaphragm 119 that surrounds the nozzle 108 and seals the nozzle 108. Further, the ejector 100 comprises a conduit 122 that connects an end-portion of the diffuser region 118 with a volume 123 behind the diaphragm 119.
• the volume 123 has a pressure that is in this embodiment proportional to or is substantially equal to the pressure P3 such that the pressure within the volume 123 pushes on the diaphragm 119 and on the nozzle 108 to move the nozzle 108 to a position at which the diaphragm 119 is sufficiently expanded such that the diaphragm 119 provides a sufficient reaction force and the nozzle is located in an adjustment position.
• the diaphragm 119 is proportioned and arranged such that the adjustment position enables substantially ideal or at least improved operating condition dependent on P3 relative to other pressures of the ejector.
• the nozzle holder 121 is provided with facility for damping the motion of the nozzle 108 such that the nozzle 108 does not change position with rapid fluctuations in pressures PI, P2 or P3. Rapid fluctuations in pressure may arise from pressure waves or shock waves in the ejector. Damping may be provided by friction within the nozzle holder 121. This friction could be provided by including a flexible ring 130 inside the nozzle holder 121.
• the ejector 100 may alternatively be provided in different forms.
• the diaphragm 119 may only partially surround the nozzle 108 and a remaining portion may be solid. Further, the diaphragm 119 may be positioned at another position than indicated in Figure 1.
• the diaphragm 119 may be located further within the ejector 100 and along the nozzle 108. Further, the diaphragm 119 may be replaced with a suitable spring mechanism (including for example a compression or
• the ejector 100 may or may not comprise the diaphragm 119 and the pressure P3 may push against a rigid wall (not shown) that is attached to the movable nozzle 108 to move the nozzle 108 until the spring mechanism provides a sufficient reaction force.
• the holder 116 may be provided in any suitable form or may not be present.
• the diaphragm 119 or the rigid wall may be arranged hold the nozzle 108.
• an end of the conduit 122 may be positioned near the outlet of the nozzle 108 in the converging region 110 or in the cylindrical region 112.
• the ejector 100 may not necessarily comprise a converging region.
• the mixing region may be incorporated in the diffusing region 118.
• the ejector may comprise an actuator that is arranged to adjust the position of the fluid nozzle 108 as a function of PI, P2 or P3.
• the ejector may comprise a pressure sensor that senses a change in PI, P2 or P3 and generates an output signal that is used to control the actuator.
• the diaphragm 119 is formed from a suitable polymeric material that has a suitable flexibility, such as a suitable rubber or a thin metallic material.
• first and second fluids may for example be refrigerants, examples of which include hydrofluorocarbons , hydrocarbons, carbon dioxide, ammonia, alcohols and water.
• Figure 4 illustrates a method of operating an ejector in accordance with an embodiment of the present invention.
• Method 400 comprises steps 402 and 404 of receiving first and second fluids.
• the method 400 also includes directing the first fluid through a nozzle of an ejector such that the pressure of the first fluid is reduced to a second pressure that is lower than the first pressure.
• the method 400 further includes drawing the second fluid such that the second fluid mixes with the first fluid that exited an outlet of the nozzle (step 408) adjusting a position of the outlet of the nozzle relative to a mixing region of the ejector dependent on the first pressure and/or the a pressure of the mixed first and second fluids to improve the efficiency of the ejector (step 410) .
• Step 408 may comprise self-adjusting the position of the outlet of the fluid nozzle.
• the heat pump refrigeration cycle 500 comprises in this example high and low temperature sub cycles (510 and 512 respectively) .
• the high temperature sub cycle 510 heat that is transferred to the ejector 100 from the heat source (such as a solar collector 504) through a vapour generator 514 causing vaporisation of the ejector cycle working fluid in the generator 514 at a temperature slightly above the saturation temperature of the heat source (such as a solar collector 504) through a vapour generator 514 causing vaporisation of the ejector cycle working fluid in the generator 514 at a temperature slightly above the saturation temperature of the
• Vapour then flows to the ejector 100 where it is accelerated (and reduced in pressure) by the nozzle of the ejector 100.
• a pump 516 may be required to generate a pressure
• the ejector 100 provides for increased
• Liquid refrigerant leaving the condenser 520 is then divided into two streams; one enters the evaporator 518 after a pressure reduction through the expansion valve 522, the other is routed back into the generator 514 after undergoing a pressure increase through the refrigerant pump 516.
• the refrigerant fluid is evaporated in the evaporator 518, absorbing heat from the environment that is being cooled, and then it is entrained back into the ejector 100 completing the cycle.
• Modelling may be based on thermodynamic
• Modelling may be aided with reference to: Eames, IW, Aphornratana, S & Haider, H 1995, ⁇ ⁇ theoretical and experimental study of a small-scale steam jet refrigerator' , International Journal of Refrigeration, vol.18, no.6, pp. 378-86.
• the ejector may be used for systems in which the inlet and exit fluids are air, water or any other type of suitable fluid.
• the inlet and exit fluids are air, water or any other type of suitable fluid.
• at least one of the inlet fluids may be a gaseous medium and the exit fluid may be a liquid.
• the at least one of the inlet fluids may be a liquid medium and the exit fluid may be a gaseous medium.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fluid Mechanics (AREA)
• Thermal Sciences (AREA)
• Jet Pumps And Other Pumps (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (8)

Cited By (7)

Families Citing this family (10)

Citations (8)

Family Cites Families (11)

• 2013
  • 2013-04-16 BR BR112014030967A patent/BR112014030967A2/pt not_active IP Right Cessation
  • 2013-04-16 CN CN201380031184.1A patent/CN104379941A/zh active Pending
  • 2013-04-16 US US14/407,452 patent/US20150152885A1/en not_active Abandoned
  • 2013-04-16 AU AU2013273913A patent/AU2013273913A1/en not_active Abandoned
  • 2013-04-16 JP JP2015516375A patent/JP2015521703A/ja active Pending
  • 2013-04-16 EP EP13803928.4A patent/EP2859242A4/en not_active Withdrawn
  • 2013-04-16 WO PCT/AU2013/000393 patent/WO2013185164A1/en active Application Filing
• 2014
  • 2014-12-08 IN IN2493MUN2014 patent/IN2014MN02493A/en unknown

Patent Citations (8)

Non-Patent Citations (1)

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