Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
  • F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
  • F24F3/14—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification
  • F24F3/1411—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification by absorbing or adsorbing water, e.g. using an hygroscopic desiccant
  • F24F3/1423—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification by absorbing or adsorbing water, e.g. using an hygroscopic desiccant with a moving bed of solid desiccants, e.g. a rotary wheel supporting solid desiccants
• • 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
  • F25B30/00—Heat pumps
• • 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
  • F25B9/004—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D17/00—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles
  • F28D17/005—Regenerative heat-exchange apparatus in which a stationary intermediate heat-transfer medium or body is contacted successively by each heat-exchange medium, e.g. using granular particles using granular particles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1032—Desiccant wheel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/104—Heat exchanger wheel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1068—Rotary wheel comprising one rotor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1084—Rotary wheel comprising two flow rotor segments
• • 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
  • F25B2500/00—Problems to be solved
  • F25B2500/01—Geometry problems, e.g. for reducing size

Definitions

• the present invention relates to an apparatus for the transfer of heat with the aid of air according to the preamble of Claim 1.
• Such an apparatus has been disclosed by the journal 'VMT VOEDINGSMIDDELTECHNOLOGIE' , vol. 25, no. 21, 8 October 1992 (NL) Zeist, pp. 75-77 'Koelproces zonder CFK's: de air cycle [Cooling process without CFCs: the air cycle]' by R.J.H. van Gerwen and S.M. van der Sluis.
• the apparatus described therein is configured as a refrigerating plant, that is to say the first means comprise a compressor and the second means comprise an expander, the first part of the regenerator is designed to take up heat from the air and the second part of the regenerator is designed to give up heat to the air.
• the outlet of the second part of the regenerator is connected to the inlet of the first means, or compressor, via a heat exchanger of conventional design.
• a heat exchanger of conventional design.
• Such an apparatus has the disadvantage that, at cooling temperatures below 0°C, the regenerator freezes up, as a result of which defrosting agents have to be added.
• the gas or air is passed through the target room or cold-storage room.
• This is essential for the ' oule-Brayton' system and differentiates this system from conventional closed systems which use CFCs, ammonia and the like. This means that a change in the composition of the gas has a direct effect on the contents of the target room. Changing the temperature of the gas is not possible, since this would lead to an unacceptable change in the temperature.
• the apparatus configured as a heat pump has the disadvantage that, at outside temperatures below 0°C, the heat exchanger freezes up, as a result of which defrosting agents have to be added.
• the aim of the present invention is to provide an apparatus wherein said freezing and the additional defrosting agents resulting therefrom can be dispensed with, wherein the energy efficiency of the apparatus is increased, wherein the thermal efficiency of the regenerator is increased, wherein the quality of the frozen products is better maintained and which can be implemented more simply and more cost- effectively.
• the apparatus By omitting the heat exchanger between the outlet of the regenerator and the inlet of the first means for changing the pressure of the air, that is to say by drawing in the air into said first means directly from the surroundings and blowing off the air from the outlet of the regenerator directly into the surroundings, the temperature difference across this heat exchanger which is no longer present is prevented, as a result of which the apparatus can operate with a higher energy efficiency.
• the heat exchanger which is no longer present is prevented from freezing up, as a result of which the heat pump can continue to operate even at outside temperatures below 0°C.
• the change in state of aggresation in the regenerator now preferably takes place in the regenerative heat exchanger, the particulate material satisfying the requirements as described in Claims 4-10. Tests have shown that with such materials no blockage of the bed takes place, while on the other hand optimum regenerative properties are achieved. More particularly, it is particularly advantageous according to the invention if the ratio of the volume of particulate material to the volume occupied by the bed is between 0.2 and 0.8. With such a ratio, it is possible to realize a good flow through the bed and, at the same time, a good exchange of sensible and latent heat and vapour.
• the equivalent diameter D of the particles of the particulate material is between 1 and 25 mm.
• the equivalent diameter D is here defined as
• V is the volume of a particle.
• A total heat-exchanging surface area of the particles in one compartment, in m 2
• r mass flow of air in kg/s
• particulate material comprises one or more of the following materials: ceramic material, glass, and/or hygroscopic material.
• the particles can per se be composed of one or more of these materials, but it is also conceivable to construct the bed from a mixture of various particles, for example a mixture of glass particles and ceramic particles.
• the regenerative heat exchanger comprises changeover means in order to be able to incorporate one compartment alternately in one or the other conduct system
• the regenerative heat exchanger comprises two compartments, which can simultaneously be incorporated in one or the other conduct system, respectively.
• Such a regenerative heat exchanger can be operated essentially continuously, the particulate material taking up heat from the passing flow of fluid in one compartment, while in the other compartment heat is given up to the flow of fluid passing through there by the particulate material.
• the particulate material has taken up sufficient sensible and latent heat in one compartment and the particulate material has surrendered its sensible and latent heat in the other compartment
• the two flows of fluid and the two compartments can be switched over with respect to one another. This alternating process can then be continually repeated.
• the refrigerating plant or heat pump comprises further compression means, the outlet of which is connected to the inlet of the first compression means, optionally via a heat exchanger exchanging heat with the surroundings.
• the compression means and the expansion means in this case each comprise a rotor, it being possible to drive the two rotors by means of a common shaft.
• Such a combined compression-expansion unit (a so-called turbo charger) generally operates optimally at rotational speeds at which it is hardly possible to supply the work required directly to the common shaft. This extra work required can be supplied by means of the further compression means.
• the regenerative heat exchanger according to the invention can according to the invention be used very advantageously in a refrigerating plant or heat pump for cooling or heating, respectively, a target room, the target room preferably being in open communication with the refrigerating plant or heat pump, respectively.
• the invention also relates to a method for operating the above- described apparatus, comprising successively in the direction of flow of
• this method is characterized in that
• the refrigerating plant or heat pump according to the invention is operated such that the pressure in the target room is kept essentially identical to the ambient pressure.
• the compression means comprise a rotor
• the temperature or capacity of a refrigerating plant or heat pump according to the invention can be advantageously controlled by controlling the rotational speed of the rotor.
• the invention furthermore relates to a method for cooling a target room using a regenerative heat exchanger according to the invention.
• a method for cooling a target room using a regenerative heat exchanger comprises the following steps: drawing in air from the atmosphere, compressing this air in at least one stage, during which process the pressure and temperature of the air increase, - passing the compressed air through a regenerative heat exchanger, the compressed air being cooled and, if necessary, moisture being removed therefrom, allowing the air which has been cooled and dehumidified in the regenerative heat exchanger to expand, - feeding the expanded air to the room which is to be cooled, drawing in air from the room to be cooled, passing the air which has been drawn in from the room to be cooled through the regenerative heat exchanger, during which process this air is heated and optionally takes up moisture.
• the invention also relates to a method for heating a target room using the regenerative heat exchanger according to the invention.
• a method for heating a target room using the regenerative heat exchanger comprises the following steps: drawing in air from the atmosphere, compressing this air in at least one stage, during which process the pressure and temperature of the air decrease, passing the compressed air through a regenerative heat exchanger, the compressed air being cooled and optionally humidified, compressing the air which has been heated and optionally humidified in the regenerative heat exchanger in at least one stage, feeding the compressed air to the room which is to be heated, drawing in air from the room to be heated, - passing the air which has been drawn in from the room to be heated through the regenerative heat exchanger, during which process this air is cooled down and optionally gives up moisture.
• the compression of the air in these methods can take place in two or more stages, the compressed air optionally being cooled by ambient air in a heat exchanger between two stages in the case of a method for cooling a target room.
• the cooling temperature or cooling capacity can advantageously be controlled by controlling the air flow rate in the first compression stage.
• Fig. 1a shows a diagrammatic view of a refrigerating plant according to the invention
• Fig. 1b shows a diagrammatic view of a so-called heat pump according to the invention
• Fig. 2a shows a refrigerating plant according to a further embodiment of the invention
• Fig. 2b shows a heat pump according to a further embodiment of the invention
• Fig. 3 shows diagrammatically a regenerative heat exchanger according to the invention of the so-called static type
• Fig. 4 shows diagrammatically a regenerative heat exchanger according to the invention of the so-called rotary type.
• a refrigerating plant 30 according to the invention which is open on both sides is shown diagrammatically.
• a heat pump 20 according to the invention which is open on both sides is shown.
• the refrigerating plant 30 and the heat pump 20 operate in accordance with the Joule-Brayton process, which in its simplest form consists of an adiabatic compression step, an isobaric heat exchange step and an adiabatic expansion step.
• the refrigerating plant 30 which is open on both sides according to Fig. 1a operates as follows:
• Air drawn in from the surroundings is passed to a compressor 32 via inlet 51.
• the air is compressed in the compressor 32, during which process the pressure and temperature of the air increase.
• the compressed air is fed via an intermediate conduct system 6, 7, in which a regenerative heat exchanger which will be described with reference to Fig. 3 is incorporated, to an expander 31 (expansion device). Expansion of the air takes place in the expander 31, during which process the pressure and temperature of the air decrease.
• the expanded, cooled air is fed via conduct 46 to the target room 34 which is to be cooled.
• This target room 34 which is to be cooled can be an essentially closed room, such as a cold store or a freezer store.
• the cooled air flows from conduct 46 freely into the cold-storage room 34.
• Air from the target room 34 which is still relatively cold or cool is discharged from the target room 34 via return conduct system 4, 5. Before this air which is still relatively cold or cool flows freely out into the surroundings, it is passed through the regenerative heat exchanger for the exchange of heat and moisture with the flow of air which is to be fed to the target room 34. During this process, the air discharged from the target room via the return conduct system 4, 5 takes up heat and moisture from the air which is to be fed to the target room 34.
• a so-called heat pump according to the invention is shown diagrammatically. Briefly, the operation of this heat pump is as follows: Air is drawn in from the surroundings via conduct 25. This air is expanded in an expander 22. During this process, the pressure and temperature of the air decrease. Then the air is fed via intermediate conduct system 6, 7, in which a regenerative heat exchanger which will be described with reference to Fig. 3 is incorporated, to a compression device 23. In the regenerative heat exchanger, the temperature of the air is increased, while the pressure will remain essentially the same. Once it arrives in the compressor 23, the air is compressed, during which process the pressure and temperature increase. The warm air is then fed via conduct 24 to the target room 21 which is to be heated.
• the heated air flows essentially freely into the target room 21, as a result of which a uniform and efficient heating of the room is made possible.
• Air is discharged from this target room 21 via a return conduct system 4, 5, which air, before flowing to the outside air via conduct 5, is passed through the regenerative heat exchanger 1 in order to preheat the air which is to be fed to the target room 21 via the intermediate conduct system 6, 7.
• Fig. 2a shows another embodiment of a refrigerating plant according to the invention.
• This refrigerating plant 40 according to Fig. 2a generally corresponds to the refrigerating plant 30 according to Fig. 1a.
• the difference is substantially that in the refrigerating plant 40 according to Fig. 2a, the compression takes place in two stages. There is a first compression stage, which takes place in the further compression means 41, and a second compression stage, which takes place in the first compression means 33.
• intermediate cooling takes place between the two stages by means of a heat exchanger 43, which is incorporated in the conduct system 42, 44 between the two compressors 41 and 33.
• the air which has been passed through the conduct system 42, 44 is cooled with the aid of ambient air, which is fed to the heat exchanger 43 via conduct 49, and is discharged again from the heat exchanger 43 to the surroundings via conduct 57.
• the compressor 33 and the expander 31 here form a so-called turbo charger, which is driven by a common shaft 45.
• Such turbo chargers generally operate optimally at rotational speeds of 50,000 to 150,000 rpm.
• the extra compressor 41 here makes it possible to supply sufficient work.
• Leakage flows can be counteracted by keeping the pressure in the room which is to be cooled essentially identical to the ambient pressure.
• This can be realized by incorporating compression means in the air flow leaving the target room.
• these compression means are located in conduct 5.
• the control for these compression means can be based on the pressure difference between the surroundings and the target room or on the volume flow rates in the conduct systems 4, 5 and 51 , 42, 44, 6, 7, 46.
• the cooling temperature or cooling capacity of a refrigerating plant 40 according to Fig. 2a can advantageously be controlled by controlling the rotational rate of the compressor 41, for example by means of a speed regulator for a rotor.
• Fig. 2b shows another embodiment of a heat pump according to the invention.
• This heat pump 29 according to Fig. 2b largely corresponds to the heat pump 20 according to Fig. 1b.
• the difference is essentially that in the heat pump 29 according to Fig. 2b the compression takes place in two stages. There is a first compression stage, which takes place in the further compression means 26, and a second compression stage, which takes place in the first compression means 23. Intermediate cooling or heating between the compression stages, such as in the refrigerating plant according to Fig. 2a, is not necessary in the heat pump 29 according to Fig 2b.
• the compressor 23 and the expander 22 form, in a corresponding manner to the compressor 33 and the expander 31 of the refrigerating plant 40 according to Fig.
• turbo charger which is driven by a common shaft 28.
• turbo chargers generally operate optimally at rotational speeds of 50,000 to 150,000 rpm.
• the extra compressor 26 here makes it possible to supply sufficient work.
• leakage flows can be counteracted by keeping the pressure in the room 21 which is to be heated essentially identical to the ambient pressure.
• compression means such as a fan, in the flow of air leaving the target room 21.
• these compression means are located in conduct 5. The control for these compression means can be based on the pressure difference between the surroundings and the target room 21 or on the volume flow rates in the conduct systems 4, 5 and 25, 6, 7, 27, 24.
• the heating temperature or the heating capacity of the heat pump 29 according to Fig. 2b can advantageously be controlled by controlling the air flow rate of the compressor 26, for example by means of a speed regulator for a rotor.
• Fig. 3 shows an example of a regenerative heat exchanger 1 according to the invention.
• This heat exchanger comprises two compartments 2 and 3, which are each provided with a packed bed of particulate material 10.
• the particles 11 thereof are essentially spherical, but differently shaped, for example irregular, particles are also very conceivable.
• the effect is achieved that the flow of fluid which is going towards the target room is passed through the right-hand compartment (instead of through the left-hand compartment), and that the flow of fluid which is discharged from the target room is passed through the left-hand compartment (instead of through the right-hand compartment).
• this rotation of the valves 8, 9 to take place with a regularity to be determined in more detail (which will be dependent on, inter alia, the process conditions, the physical properties of the particulate material, etc.)
• the effect is achieved that alternately the bed is always taking up heat in one compartment while the bed is giving up heat in the other compartment.
• the bed of such particulate material is also very able to bind to itself condensation or precipitation, such as deposition of moisture or ice, and then to give it up to the other flow of fluid.
• condensation or precipitation such as deposition of moisture or ice
• one of the flows of the fluid can be dehumidified.
• the air which is to be fed to the refrigerating plant is hereby simultaneously cooled and dehumidified in the regenerative heat exchanger, it being possible to discharge the moisture through the flow of fluid discharged from the cold-storage room after the valves have been switched over, while the temperature of the particulate material is simultaneously lowered. In this way, the regenerative heat exchanger 1 is prevented from becoming blocked as a consequence of the deposition of moisture and/or ice.
• a further advantage is that the flow of air which has been dehumidified in the regenerative heat exchanger 1 will not form any deposition of moisture or ice in further process steps in a refrigerating plant or heat pump either, so that here too the apparatus is prevented from becoming defective.
• Fig. 4 shows a regenerative heat exchanger 70 according to the invention of the so-called rotary type.
• This regenerative heat exchanger 70 consists essentially of a cylinder 74 which is subdivided into compartments extending in the longitudinal direction thereof.
• the cylinder 74 shown in Fig. 4 comprises three compartments 71, 72 and 73, which are obtained by installing three partitions 75, 76 and 77 in the cylinder 74, which partitions are fixed to one another at the longitudinal centre axis of the cylinder 74.
• Each compartment thus obtained is filled with a bed 10 of particulate material 11.
• the cylinder 74 is arranged so as to be rotatable about axis 78.
• Feed conducts 4, 6 and discharge conducts 5, 7 are arranged at the ends of the cylinder 74.
• the conducts 4 and 5 here form part of one conduct system, while the conducts 6 and 7 form part of another conduct system.
• fluid for example air
• the effect is achieved that the various compartments are successively incorporated in one conduct system (for example 4, 5) or the other conduct system (for example 6, 7).
• regenerative heat exchanger 70 The operation of the regenerative heat exchanger 70 is, as will be clear, otherwise in accordance with the operation as has been described with reference to Fig. 3 for regenerative heat exchanger 1. It will also be clear, then, that the regenerative heat exchanger 1 from Fig. 1a, 1b, 2a and 2b can readily be replaced by a regenerative heat exchanger 70 of the rotary type.
• feed conduct 6 can be a discharge conduct, discharge conduct 7 then becoming a feed conduct. Accordingly, it is possible to reverse the direction of flow in the conducts 4 and 5.
• valves 8, 9 many other changeover means for making one or the other flow of fluid flow through the respective compartments alternately are also conceivable.
• the regenerative heat exchanger comprises one, preferably cylindrical, compartment which rotates about its axis. The particulate material in this compartment is then exposed in turn to one or the other flow of fluid.
• heat exchangers, compressors, expanders, etc. can also be connected upstream, intermediately or downstream.
• such apparatuses should comprise at least one expansion device, at least one compression device, and at least one regenerative heat exchanger arranged between a compression device and expansion device.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Steam Or Hot-Water Central Heating Systems (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=19865487

Family Applications (1)

Country Status (5)

Families Citing this family (7)

Family Cites Families (10)

• 1995
  • 1995-01-24 NL NL9500130A patent/NL9500130A/nl not_active Application Discontinuation
• 1996
  • 1996-01-24 WO PCT/NL1996/000042 patent/WO1996023188A2/en active IP Right Grant
  • 1996-01-24 EP EP96902509A patent/EP0805942B1/de not_active Expired - Lifetime
  • 1996-01-24 DE DE69612546T patent/DE69612546T2/de not_active Expired - Fee Related
  • 1996-01-24 AU AU46792/96A patent/AU4679296A/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events