CA2214409A1 - Arrangement in connection with an air conditioning unit comprising heat recovery means and means for introducing additional heating and cooling - Google Patents
Arrangement in connection with an air conditioning unit comprising heat recovery means and means for introducing additional heating and cooling Download PDFInfo
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- CA2214409A1 CA2214409A1 CA002214409A CA2214409A CA2214409A1 CA 2214409 A1 CA2214409 A1 CA 2214409A1 CA 002214409 A CA002214409 A CA 002214409A CA 2214409 A CA2214409 A CA 2214409A CA 2214409 A1 CA2214409 A1 CA 2214409A1
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- Prior art keywords
- air
- heat recovery
- arrangement
- cooling
- supply air
- Prior art date
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Links
- 238000011084 recovery Methods 0.000 title claims abstract description 46
- 238000010438 heat treatment Methods 0.000 title claims abstract description 38
- 238000001816 cooling Methods 0.000 title claims abstract description 35
- 238000004378 air conditioning Methods 0.000 title claims abstract description 10
- 239000007788 liquid Substances 0.000 claims description 7
- 230000000694 effects Effects 0.000 claims description 2
- 238000011144 upstream manufacturing Methods 0.000 claims description 2
- 230000005611 electricity Effects 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000007710 freezing Methods 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- FDSYTWVNUJTPMA-UHFFFAOYSA-N 2-[3,9-bis(carboxymethyl)-3,6,9,15-tetrazabicyclo[9.3.1]pentadeca-1(15),11,13-trien-6-yl]acetic acid Chemical compound C1N(CC(O)=O)CCN(CC(=O)O)CCN(CC(O)=O)CC2=CC=CC1=N2 FDSYTWVNUJTPMA-UHFFFAOYSA-N 0.000 description 2
- 230000002730 additional effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000010257 thawing Methods 0.000 description 2
- 239000002918 waste heat Substances 0.000 description 2
- 101100345589 Mus musculus Mical1 gene Proteins 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000002277 temperature effect Effects 0.000 description 1
Classifications
-
- 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
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F12/00—Use of energy recovery systems in air conditioning, ventilation or screening
- F24F12/001—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air
-
- 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
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
- F24F11/83—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers
- F24F11/84—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling the supply of heat-exchange fluids to heat-exchangers using valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F12/00—Use of energy recovery systems in air conditioning, ventilation or screening
- F24F12/001—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air
- F24F2012/007—Use of energy recovery systems in air conditioning, ventilation or screening with heat-exchange between supplied and exhausted air using a by-pass for bypassing the heat-exchanger
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2110/00—Control inputs relating to air properties
- F24F2110/10—Temperature
-
- 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
- F24F2203/1056—Rotary wheel comprising a reheater
-
- 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
- F24F2203/1072—Rotary wheel comprising two rotors
-
- 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
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F6/00—Air-humidification, e.g. cooling by humidification
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/56—Heat recovery units
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P80/00—Climate change mitigation technologies for sector-wide applications
- Y02P80/10—Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
- Y02P80/15—On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Central Air Conditioning (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The present invention relates to an arrangement in connection with an air conditioning unit, comprising means (15, 16, 19, 20) for conveying exhaust and supply air through the air conditioning unit, a heat recovery unit having at least two stages (1, 2) and means for introducing additional heat or cooling power into the supply air. To enhance heat transfer, the means for introducing additional heat or cooling power into the supply air comprise at least one heating device or cooling device (3) disposed between the stages (1, 2) of the heat recovery unit in the exhaust air flow or separate air flow, adapted to change the temperature of the exhaust air and thereby to influence the temperature of the supply air indirectly through the heat recovery unit.
Description
WO 96~27767 PCT/F196/00123 Arrangement in connection with an air conditioning unit comprising heat recovery means and means for introducing additional heating and cooling.
The present invention relates to an arrangement in connection with an air conditioning unit, comprising means for conveying exhaust and supply air through the air conditioning unit, a heat recovery unit having at least two stages and means for introducing additional heat or cooling power into the supply air.
Arrangements of this kind are nowadays ~r ~ 1l in air conditioning solutions for buildings. Energy is transferred from air to air mainly indirectly through heat exchangers. Ventilating installations are today almost without exception provided with heat recovery units. Also indirect evaporative cooling has increas-ingly been introduced into the market. In such cooling,exhaust air is cooled by humidification, whereafter the temperature effect will be transferred through a heat recovery stage to the supply air, which is cooled. The heat recovery unit may be a plate heat ~ch~nger, a rotor, a radiator combination operating with a fluid, or a heat pump, depending on the reguirements on hygiene, technical requirements and space solutions.
Despite the good efficiency of heat recovery units, additional heat is normally ~eeded in ventilation installations in order for the temperature of the supply air not to be too low, in particular if the amount of energy transmitted from the exhaust air must be limited on account of frosting of the exhaust air. The additional heat has conventionally been introduced into the supply air after the heat recovery unit with a water radiator or an electric heater. The use of electricity for heating of air is, however, questionable, and this will be a growing trend in the future. The exhaust air side of heat recovery units becomes frosted when the humidity in the exhaust air is condensed onto the W 096/27767 PCT~96/00123 surface of the heat recovery unit if the surface temperature of the heat recovery unit is below zero.
Depending on the relative humidity of the exhaust air, this will take place when the outdoor temperature is -15~C or lower. The defrosting of a plate heat exchanger,for example, takes place in such a way that part of the supply air is conveyed past the plate heat exchanger, or the entry of supply air to various sections of the heat exchanger in turn is prevented, which will make the warm exhaust air defrost the frosted areas. During the defrosting step, the efficiency of heat recovery will be impaired. The operation of the frosting step and anti-freezing of the additional heating radiator requires special automatics and also electro-mech~nical devices in order that the operation may be realized.
It is an object of the invention to provide an arrangement wherewith the drawbacks of the prior art can be ~l;m;nated. This has been achieved with the arrange-ment of the invention, which is characterized in that the means for introducing additional heat or cooling power into the supply air comprise at least one heating device or/and cooling device disposed between the stages of the heat recovery unit in the exhaust air flow or separate air flow or a combined heating-cooling device adapted to change the temperature of the exhaust air and thereby to influence the temperature of the supply air indirectly through the heat recovery unit.
An advantage of the invention is first of all its good basic heat recovery efficiency and very high community thermal energy efficiency in the heating and/or cooling stage. Furthermore, the overall solution is inexpensive and easy and reliable in operation and has a low consumption of electricity. The good thermal energy efficiency in the heating stage is based on the possibility to use low-grade thermal energy, such as W096/27767 PC~AF~6/VO12~
waste heat or condensation heat, which may even be free o~ cost if it is not reclaimable in any other ~nne~.
The low consumption of electricity is based on the fact that the radiator surfaces are effectively utilized in all stages, and thus the air flow includes no components causing extra air resistance. The plate heat exchanger is not provided with a liquid pump consuming elec-tricity. The conventional components provided in the supply and exhaust air flows can advantageously supplement the outcome. In winter, the supply air flow passes through the first stage of the heat exchanger and is heated by the exhaust air, whereafter it is trans-ferred to the following stages of heat recovery, in which the temperature reaches a basic level that may be sufficient as such. If this is not enough in the case of air heating, for example, the supply air passes through an additional heating radiator. Since the additional heating radiator is connected in series with the exhaust air heating radiator, these may have a control circuit in ~o,-l,nu-~.
In summer, the supply air flow may by-pass heat exchangers through a by-pass route, for example, if no change of state is desired. If the sy~ is provided with humidifying cooling of the exhaust air, the supply air is cooled stepwise in passing through the heat recovery stages. If the temperature is not low enough, it is possible to provide the supply air flow with a cooling radiator.
In winter, the exhaust air flow first passes through the last heat recovery stage on the supply air side, which will decrease the temperature of the exhaust air. Thereafter the radiatûr in the exhaust air flow will heat the exhaust air before it is passed to the next heat recovery stage, delivering its additional thermal energy and possibly the thermal energy re~in;ng W 096/27767 PCTA~96/00123 from the preceding stage or part of it to the supply air through the heat recovery unit.
In summer, it is possible to cool the exhaust air flow by humidifying either in one stage in connec-tion with the heat recovery stages or in separatehumidifiers in the flow direction of the exhaust air prior to the heat recovery stages. If this is not suf-ficient, the heating radiator provided in the exhaust air flow can be used as a cooling radiator. Additional power can be achieved by furnishing the supply air flow either with a separate cooling radiator or a combined heating and cooling radiator connected in series with the radiator in the exhaust air flow.
The essential difference to conventional oper-ation is that the temperature of the additional energymay be at a lower level, since in normal operation there is no risk of freezing, while the temperature difference of the heated medium and the heat-delivering medium can still be advantageous. With the conventional arrange-ment, the temperature of the heating medium in the inletpipe cannot be lower than 30-40~C, which is the normal temperature of water when ventilation is stopped. As a rule, the design temperature for normal use is +60~ in and +40~ out. With the invention, an energy source may well be used having a temperature of +25~C, for example, in which case the corresponding temperatures may be +25~C in and +20~C out, since the purpose is to heat exhaust air having a temperature above 0~C, yet lower than the temperature of the air exiting the room. At the same time, the automatics can be simplified as regards anti-freezing, anti-frosting and possibly temperature control. Also varying water flows can be passed through the additional heating radiator(s) without any risk of the water becoming frozen.
In the following the invention will be explained W O 96/27767 PC~6~0~123 in greater detail by means of preferred embodiments shown in the accompanying drawing, in which Figure 1 is a schematic side view of a preferred embodiment of an arrangement of the invention, Figure 2 is a schematic side view of a second embodiment of the arrangement of the invention, Figure 3 is a schematic side view of a third embodiment of the arrangement of the invention, Figure 4 is a schematic side view of a fourth embodiment of the arrangement of the invention, Figure 5 is a schematic side view of a fifth em-bodiment of the arrangement of the invention, Figure 6 is a schematic side view of a sixth em-bodiment of the arrangement of the invention, Figure 7 is a schematic side view of a seventh emboA;~nt of the arrangement of the invention, Figure 8 is a schematic side view of an eighth embodiment of the arrangement of the invention, Figure 9 is a schematic side view of an altern-ative implementation of the embodiment of Figure 8, Figure 10 is a schematic side view of a secondalternative implementation of the embodiment of Figure 8, and Figure 11 is a schematic side view of an altern-ative implementation of a detail of the arrangement ofthe invention.
In Figure 1, reference numeral 1 denotes the first stage and reference 2 the second stage of a heat recovery arrangement in the flow direction of supply air. These stages are plate heat exchangers. Reference 3 denotes an additional heating device located between the heat recovery stages, e.g. an additional heating ~ radiator, operating if desired at a low temperature level, for example with waste heat or ~onA~n~ation heat that is supplied to the radiator through service pipes W 096/27767 PCTA~96/00123 8. It is to be noted that Figure 1 is simplified over against the actual construction, wherefore the figure is to be understood only as a symbolic representation.
Reference 14 in Figure 1 denotes the jacket of an air conditioning unit, reference 15 a supply air fan and reference 16 an exhaust air fan or separate air fan.
In this context, separate air denotes other air than exhaust air from the ventilation, which delivers energy to the supply air or in which a change of state indirectly affects the state of the supply air. An example of separate air could be outdoor air or a mixture of outdoor air and indoor air. Reference 17 denotes a possible supply air filter and reference 18 a possible exhaust air filter, respectively. Reference 19 denotes a possible damper for supply air and reference 20 a possible damper for exhaust air. In addition to these details, the apparatus can be provided with conventional components, such as an air mixing unit, electrical outfit, etc.
Figure 1 clearly shows the main idea of the invention, i.e. that the means for introducing addi-tional heat or cooling power into the supply air com-prise at least one heating device or cooling device 3 disposed between the stages 1, 2 of the heat recovery unit in the exhaust air flow or separate air flow, adapted to change the temperature of the exhaust air and thereby to influence the temperature of the supply air indirectly through the heat recovery unit.
Figure 1 additionally shows one possible embodi-ment. Reference 27 denotes a device consuming thermal energy and reference 28 a heat-delivering device, respectively. The device 27 consuming thermal energy or/and the heat-delivering device 28 is/are preferably connected to the same liquid circuit in series with the heating or cooling device 3, and further at a point up-WO 96127767 P'CT~96/OOlZ3 stream of the heating or cooling device 3 in the li~uid flow direction.
The embodiment of Figure 2 shows a heat recovery arrangement in which references 1 and 2 denote the stages of the heat recovery unit, reference 3 an addi-tional heating radiator and reference 8 service pipes.
Reference 13 denotes an air flow by-pass duct system wherein damper 12 controls the air flow. The damper 12 can be used in summer conditions, for instance, when it is not desired to transfer thermal energy to the supply air.
Figure 3 illustrates by references 1 and 2 the stages of the heat recovery unit and by means of reference 3 a heating air radiator that is located between the heat recovery stages in the exhaust air flow. Reference 4 denotes a heating radiator in the supply air flow; the piping of the liquid side of this radiator is connected in series with the heating radi-ator 3 indirectly affecting the temperature of the supply air. soth radiators can be controlled with a single common automatic control circuit, for instance.
In this embodiment, the radiator 3 indirectly affects the supply air flow through the heat recovery unit, and radiator 4 affects it directly on account of being located in the supply air flow.
Figure 4 shows an arrangement in accordance with Figure 1, to which an exhaust air humidifier denoted by reference 5 has been incorporated. This humidifier may be a separate humidifier, a humidifying nozzle or a heat recovery unit provided with a humidification arrange-ment. It is possible to duplicate the solution in connection with each stage of the heat recovery unit, or upstream of the heat recovery unit in the flow direction of the exhaust air.
It is evident that devices 27 and 28 can also be W096/27767 PCTn~96/00123 incorporated into the embodiments of Figures 2-4 as shown in Figure 1.
Figure 5 shows an arrangement in accordance with Figure 4, in which the additional heating radiator 6 has two functions, i.e. heating and cooling. These functions can be performed with the same radiator 6.
Figure 6 shows two stages 1 and 2 of the heat recovery unit and a humidifier 5. A combined radiator 6 enabling heating and cooling is operationally - i.e. on the liquid side - connected with pipes 11 in series with a second combined radiator 7 provided in the supply air flow. By this arrangement, it is possible to ~nh~nc~ the effect of the heating and cooling stages. In this embodiment, radiator 6 indirectly affects the supply air flow through the heat recovery unit, and radiator 7 affects it directly on account of being located in the supply air flow.
Figure 7 shows the basic idea of the solution of Figure 1 implemented with rotary recovery cells illus-trated by references 21 and 22. Other operationalalternatives can be implemented in a corresponding way.
Radiator 3 is located in the exhaust air flow.
Figure 8 correspondingly shows the basic idea of the solution of Figure 1 implemented with a radiator solution employing some medium. Radiators provided in the supply air flow are denoted by references 23 and 24 and radiators provided in the exhaust air flow by references 25 and 26, respectively.
With regard to the solution of Figure 8, it can be stated that a particularly preferred embodiment is achieved by connecting radiators 23-26 in series in the same flow circuit on the counter-current principle, as shown in Figure 9. Furthermore, for example radiators 23 and 24 can be combined into radiator 234 and radiators 25 and 26 can be separate, as shown in Figure 10. It is WO 96/27767 PCT~F~96~00~23 naturally also possible to implement this constructional alternative vice versa.
The heating device and/or cooling device 3 can also be fitted in a by-pass duct 110 as shown in Figure 11. Figure 11 is based on Figure 8. Figure 11 shows only the radiators 25, 26 on the exhaust air side, in other respects the embodiment of Figure 11 corresponds to the embodiment of Figure 8. In this embo~i~ent, the air flow can be directed with baffle 111 to pass via by-pass duct 110 through the heating device 3, or alternatively directly in such a way that the air does not flow into by-pass duct 110, but past the heating device 3. It is also possible to make the construction such that one of the radiators of the heat recovery unit can be by-passed. Also this detail is shown in Figure 11, wherein reference 112 denotes a second baffle that can be turned into the positions shown in the figure, thus enabling the air flow to be directed in the desired manner.
Figure 11 shows various possibilities for air flow by means of arrows.
Devices 27 and 28 in accordance with Figure 1 can also be incorporated into the embodiments of Figures 5-8, as has been explained in connection with Figure 1.
The above exemplary embodiments are not to be construed as limiting the invention, but the invention can be modified with complete freedom within the purview of the claims. It will be appreciated that the arrangement of the invention or its details need not necessarily be exactly as shown in the figures, but other kinds of solutions are possible as well. It is to be noted, for example, that even though the figures present solutions in which one radiator located between , the heat recovery stages and one radiator fitted in the supply air flow, this is not the only possibility, but it is possible to use more radiators at these points, W O 96/27767 PCTn~96/00123 etc. Even though the figures primarily illustrate embodiments with a plate heat exchanger, the invention is well suitable for other equipment stated above, or combinations of such equipment.
The present invention relates to an arrangement in connection with an air conditioning unit, comprising means for conveying exhaust and supply air through the air conditioning unit, a heat recovery unit having at least two stages and means for introducing additional heat or cooling power into the supply air.
Arrangements of this kind are nowadays ~r ~ 1l in air conditioning solutions for buildings. Energy is transferred from air to air mainly indirectly through heat exchangers. Ventilating installations are today almost without exception provided with heat recovery units. Also indirect evaporative cooling has increas-ingly been introduced into the market. In such cooling,exhaust air is cooled by humidification, whereafter the temperature effect will be transferred through a heat recovery stage to the supply air, which is cooled. The heat recovery unit may be a plate heat ~ch~nger, a rotor, a radiator combination operating with a fluid, or a heat pump, depending on the reguirements on hygiene, technical requirements and space solutions.
Despite the good efficiency of heat recovery units, additional heat is normally ~eeded in ventilation installations in order for the temperature of the supply air not to be too low, in particular if the amount of energy transmitted from the exhaust air must be limited on account of frosting of the exhaust air. The additional heat has conventionally been introduced into the supply air after the heat recovery unit with a water radiator or an electric heater. The use of electricity for heating of air is, however, questionable, and this will be a growing trend in the future. The exhaust air side of heat recovery units becomes frosted when the humidity in the exhaust air is condensed onto the W 096/27767 PCT~96/00123 surface of the heat recovery unit if the surface temperature of the heat recovery unit is below zero.
Depending on the relative humidity of the exhaust air, this will take place when the outdoor temperature is -15~C or lower. The defrosting of a plate heat exchanger,for example, takes place in such a way that part of the supply air is conveyed past the plate heat exchanger, or the entry of supply air to various sections of the heat exchanger in turn is prevented, which will make the warm exhaust air defrost the frosted areas. During the defrosting step, the efficiency of heat recovery will be impaired. The operation of the frosting step and anti-freezing of the additional heating radiator requires special automatics and also electro-mech~nical devices in order that the operation may be realized.
It is an object of the invention to provide an arrangement wherewith the drawbacks of the prior art can be ~l;m;nated. This has been achieved with the arrange-ment of the invention, which is characterized in that the means for introducing additional heat or cooling power into the supply air comprise at least one heating device or/and cooling device disposed between the stages of the heat recovery unit in the exhaust air flow or separate air flow or a combined heating-cooling device adapted to change the temperature of the exhaust air and thereby to influence the temperature of the supply air indirectly through the heat recovery unit.
An advantage of the invention is first of all its good basic heat recovery efficiency and very high community thermal energy efficiency in the heating and/or cooling stage. Furthermore, the overall solution is inexpensive and easy and reliable in operation and has a low consumption of electricity. The good thermal energy efficiency in the heating stage is based on the possibility to use low-grade thermal energy, such as W096/27767 PC~AF~6/VO12~
waste heat or condensation heat, which may even be free o~ cost if it is not reclaimable in any other ~nne~.
The low consumption of electricity is based on the fact that the radiator surfaces are effectively utilized in all stages, and thus the air flow includes no components causing extra air resistance. The plate heat exchanger is not provided with a liquid pump consuming elec-tricity. The conventional components provided in the supply and exhaust air flows can advantageously supplement the outcome. In winter, the supply air flow passes through the first stage of the heat exchanger and is heated by the exhaust air, whereafter it is trans-ferred to the following stages of heat recovery, in which the temperature reaches a basic level that may be sufficient as such. If this is not enough in the case of air heating, for example, the supply air passes through an additional heating radiator. Since the additional heating radiator is connected in series with the exhaust air heating radiator, these may have a control circuit in ~o,-l,nu-~.
In summer, the supply air flow may by-pass heat exchangers through a by-pass route, for example, if no change of state is desired. If the sy~ is provided with humidifying cooling of the exhaust air, the supply air is cooled stepwise in passing through the heat recovery stages. If the temperature is not low enough, it is possible to provide the supply air flow with a cooling radiator.
In winter, the exhaust air flow first passes through the last heat recovery stage on the supply air side, which will decrease the temperature of the exhaust air. Thereafter the radiatûr in the exhaust air flow will heat the exhaust air before it is passed to the next heat recovery stage, delivering its additional thermal energy and possibly the thermal energy re~in;ng W 096/27767 PCTA~96/00123 from the preceding stage or part of it to the supply air through the heat recovery unit.
In summer, it is possible to cool the exhaust air flow by humidifying either in one stage in connec-tion with the heat recovery stages or in separatehumidifiers in the flow direction of the exhaust air prior to the heat recovery stages. If this is not suf-ficient, the heating radiator provided in the exhaust air flow can be used as a cooling radiator. Additional power can be achieved by furnishing the supply air flow either with a separate cooling radiator or a combined heating and cooling radiator connected in series with the radiator in the exhaust air flow.
The essential difference to conventional oper-ation is that the temperature of the additional energymay be at a lower level, since in normal operation there is no risk of freezing, while the temperature difference of the heated medium and the heat-delivering medium can still be advantageous. With the conventional arrange-ment, the temperature of the heating medium in the inletpipe cannot be lower than 30-40~C, which is the normal temperature of water when ventilation is stopped. As a rule, the design temperature for normal use is +60~ in and +40~ out. With the invention, an energy source may well be used having a temperature of +25~C, for example, in which case the corresponding temperatures may be +25~C in and +20~C out, since the purpose is to heat exhaust air having a temperature above 0~C, yet lower than the temperature of the air exiting the room. At the same time, the automatics can be simplified as regards anti-freezing, anti-frosting and possibly temperature control. Also varying water flows can be passed through the additional heating radiator(s) without any risk of the water becoming frozen.
In the following the invention will be explained W O 96/27767 PC~6~0~123 in greater detail by means of preferred embodiments shown in the accompanying drawing, in which Figure 1 is a schematic side view of a preferred embodiment of an arrangement of the invention, Figure 2 is a schematic side view of a second embodiment of the arrangement of the invention, Figure 3 is a schematic side view of a third embodiment of the arrangement of the invention, Figure 4 is a schematic side view of a fourth embodiment of the arrangement of the invention, Figure 5 is a schematic side view of a fifth em-bodiment of the arrangement of the invention, Figure 6 is a schematic side view of a sixth em-bodiment of the arrangement of the invention, Figure 7 is a schematic side view of a seventh emboA;~nt of the arrangement of the invention, Figure 8 is a schematic side view of an eighth embodiment of the arrangement of the invention, Figure 9 is a schematic side view of an altern-ative implementation of the embodiment of Figure 8, Figure 10 is a schematic side view of a secondalternative implementation of the embodiment of Figure 8, and Figure 11 is a schematic side view of an altern-ative implementation of a detail of the arrangement ofthe invention.
In Figure 1, reference numeral 1 denotes the first stage and reference 2 the second stage of a heat recovery arrangement in the flow direction of supply air. These stages are plate heat exchangers. Reference 3 denotes an additional heating device located between the heat recovery stages, e.g. an additional heating ~ radiator, operating if desired at a low temperature level, for example with waste heat or ~onA~n~ation heat that is supplied to the radiator through service pipes W 096/27767 PCTA~96/00123 8. It is to be noted that Figure 1 is simplified over against the actual construction, wherefore the figure is to be understood only as a symbolic representation.
Reference 14 in Figure 1 denotes the jacket of an air conditioning unit, reference 15 a supply air fan and reference 16 an exhaust air fan or separate air fan.
In this context, separate air denotes other air than exhaust air from the ventilation, which delivers energy to the supply air or in which a change of state indirectly affects the state of the supply air. An example of separate air could be outdoor air or a mixture of outdoor air and indoor air. Reference 17 denotes a possible supply air filter and reference 18 a possible exhaust air filter, respectively. Reference 19 denotes a possible damper for supply air and reference 20 a possible damper for exhaust air. In addition to these details, the apparatus can be provided with conventional components, such as an air mixing unit, electrical outfit, etc.
Figure 1 clearly shows the main idea of the invention, i.e. that the means for introducing addi-tional heat or cooling power into the supply air com-prise at least one heating device or cooling device 3 disposed between the stages 1, 2 of the heat recovery unit in the exhaust air flow or separate air flow, adapted to change the temperature of the exhaust air and thereby to influence the temperature of the supply air indirectly through the heat recovery unit.
Figure 1 additionally shows one possible embodi-ment. Reference 27 denotes a device consuming thermal energy and reference 28 a heat-delivering device, respectively. The device 27 consuming thermal energy or/and the heat-delivering device 28 is/are preferably connected to the same liquid circuit in series with the heating or cooling device 3, and further at a point up-WO 96127767 P'CT~96/OOlZ3 stream of the heating or cooling device 3 in the li~uid flow direction.
The embodiment of Figure 2 shows a heat recovery arrangement in which references 1 and 2 denote the stages of the heat recovery unit, reference 3 an addi-tional heating radiator and reference 8 service pipes.
Reference 13 denotes an air flow by-pass duct system wherein damper 12 controls the air flow. The damper 12 can be used in summer conditions, for instance, when it is not desired to transfer thermal energy to the supply air.
Figure 3 illustrates by references 1 and 2 the stages of the heat recovery unit and by means of reference 3 a heating air radiator that is located between the heat recovery stages in the exhaust air flow. Reference 4 denotes a heating radiator in the supply air flow; the piping of the liquid side of this radiator is connected in series with the heating radi-ator 3 indirectly affecting the temperature of the supply air. soth radiators can be controlled with a single common automatic control circuit, for instance.
In this embodiment, the radiator 3 indirectly affects the supply air flow through the heat recovery unit, and radiator 4 affects it directly on account of being located in the supply air flow.
Figure 4 shows an arrangement in accordance with Figure 1, to which an exhaust air humidifier denoted by reference 5 has been incorporated. This humidifier may be a separate humidifier, a humidifying nozzle or a heat recovery unit provided with a humidification arrange-ment. It is possible to duplicate the solution in connection with each stage of the heat recovery unit, or upstream of the heat recovery unit in the flow direction of the exhaust air.
It is evident that devices 27 and 28 can also be W096/27767 PCTn~96/00123 incorporated into the embodiments of Figures 2-4 as shown in Figure 1.
Figure 5 shows an arrangement in accordance with Figure 4, in which the additional heating radiator 6 has two functions, i.e. heating and cooling. These functions can be performed with the same radiator 6.
Figure 6 shows two stages 1 and 2 of the heat recovery unit and a humidifier 5. A combined radiator 6 enabling heating and cooling is operationally - i.e. on the liquid side - connected with pipes 11 in series with a second combined radiator 7 provided in the supply air flow. By this arrangement, it is possible to ~nh~nc~ the effect of the heating and cooling stages. In this embodiment, radiator 6 indirectly affects the supply air flow through the heat recovery unit, and radiator 7 affects it directly on account of being located in the supply air flow.
Figure 7 shows the basic idea of the solution of Figure 1 implemented with rotary recovery cells illus-trated by references 21 and 22. Other operationalalternatives can be implemented in a corresponding way.
Radiator 3 is located in the exhaust air flow.
Figure 8 correspondingly shows the basic idea of the solution of Figure 1 implemented with a radiator solution employing some medium. Radiators provided in the supply air flow are denoted by references 23 and 24 and radiators provided in the exhaust air flow by references 25 and 26, respectively.
With regard to the solution of Figure 8, it can be stated that a particularly preferred embodiment is achieved by connecting radiators 23-26 in series in the same flow circuit on the counter-current principle, as shown in Figure 9. Furthermore, for example radiators 23 and 24 can be combined into radiator 234 and radiators 25 and 26 can be separate, as shown in Figure 10. It is WO 96/27767 PCT~F~96~00~23 naturally also possible to implement this constructional alternative vice versa.
The heating device and/or cooling device 3 can also be fitted in a by-pass duct 110 as shown in Figure 11. Figure 11 is based on Figure 8. Figure 11 shows only the radiators 25, 26 on the exhaust air side, in other respects the embodiment of Figure 11 corresponds to the embodiment of Figure 8. In this embo~i~ent, the air flow can be directed with baffle 111 to pass via by-pass duct 110 through the heating device 3, or alternatively directly in such a way that the air does not flow into by-pass duct 110, but past the heating device 3. It is also possible to make the construction such that one of the radiators of the heat recovery unit can be by-passed. Also this detail is shown in Figure 11, wherein reference 112 denotes a second baffle that can be turned into the positions shown in the figure, thus enabling the air flow to be directed in the desired manner.
Figure 11 shows various possibilities for air flow by means of arrows.
Devices 27 and 28 in accordance with Figure 1 can also be incorporated into the embodiments of Figures 5-8, as has been explained in connection with Figure 1.
The above exemplary embodiments are not to be construed as limiting the invention, but the invention can be modified with complete freedom within the purview of the claims. It will be appreciated that the arrangement of the invention or its details need not necessarily be exactly as shown in the figures, but other kinds of solutions are possible as well. It is to be noted, for example, that even though the figures present solutions in which one radiator located between , the heat recovery stages and one radiator fitted in the supply air flow, this is not the only possibility, but it is possible to use more radiators at these points, W O 96/27767 PCTn~96/00123 etc. Even though the figures primarily illustrate embodiments with a plate heat exchanger, the invention is well suitable for other equipment stated above, or combinations of such equipment.
Claims (6)
1. An arrangement in connection with an air conditioning unit, comprising means (15, 16, 19, 20) for conveying exhaust and supply air through the air conditioning unit, a heat recovery unit having at least two stages (1, 2) and means for introducing additional heat or cooling power into the supply air, c h a r a c t e r i z e d in that the means for introducing additional heat or cooling power into the supply air comprise at least one heating device or/and cooling device (3, 6), or a combined heating-cooling device disposed between the stages (1, 2) of the heat recovery unit in the exhaust air flow or separate air flow, which device is adapted to change the temperature of the exhaust air and thereby to influence the temperature of the supply air indirectly through the heat recovery unit.
2. An arrangement as claimed in claim 1, c h a r a c t e r i z e d in that it comprises means (12, 13) wherewith the exhaust air, supply air, separate air, or exhaust and supply air can be conveyed past the heat recovery unit.
3. An arrangement as claimed in claim 1 or 2, c h a r a c t e r i z e d in that it comprises at least one heating or cooling means (4, 7) fitted in the supply air flow, the liquid side (9, 11) of which is connected in series with the heating or/and cooling device (3, 6) provided in the exhaust air flow or separate air flow, said entirety being adapted together to produce both an indirect and a direct effect on the temperature of the supply air.
4. An arrangement as claimed in any one of the preceding claims 1-4, c h a r a c t e r i z e d in that the arrangement comprises at least one device (27) consuming thermal energy or/and a heat-delivering device (28), which are connected in the same liquid circuit in series with at least one heating or cooling device (3, 6) upstream of the heating or/and cooling device (3, 6) in the liquid flow direction.
s. An arrangement as claimed in any one of the preceding claims 1-4, c h a r a c t e r i z e d in that at least one humidifier (5) for cooling the air is fitted in the exhaust air flow or separate air flow.
6. An arrangement as claimed in claim 1, c h a r a c t e r i z e d in that the heating or/and cooling device (3, 6) is fitted in a by-pass duct (110) that can be closed separately.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FI951011 | 1995-03-03 | ||
FI951011A FI100132B (en) | 1995-03-03 | 1995-03-03 | Arrangement in connection with an air handling unit |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2214409A1 true CA2214409A1 (en) | 1996-09-12 |
Family
ID=8542972
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA002214409A Abandoned CA2214409A1 (en) | 1995-03-03 | 1996-03-01 | Arrangement in connection with an air conditioning unit comprising heat recovery means and means for introducing additional heating and cooling |
Country Status (8)
Country | Link |
---|---|
CA (1) | CA2214409A1 (en) |
DE (1) | DE19681367T1 (en) |
DK (1) | DK100097A (en) |
FI (1) | FI100132B (en) |
NO (1) | NO974030L (en) |
RU (1) | RU2168116C2 (en) |
SE (1) | SE9703156L (en) |
WO (1) | WO1996027767A1 (en) |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2255181A1 (en) * | 1997-12-02 | 1999-06-02 | Louis J. Bailey | Integrated system for heating, cooling and heat recovery ventilation |
DE19824315B4 (en) * | 1997-12-11 | 2005-10-06 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Heat pump compact device with integrated primary energy heat source for controlled ventilation and heat energy supply of low-energy buildings or passive houses |
NL1011206C2 (en) * | 1999-02-03 | 2000-08-07 | Barend Jan Marinus Hemmes | Ventilation unit. |
RU2449223C1 (en) * | 2008-04-16 | 2012-04-27 | Мицубиси Электрик Корпорейшн | Heat exchange fan |
FI20085412L (en) * | 2008-05-06 | 2009-11-07 | Flaekt Woods Ab | Procedure for using outdoor air to cool room devices |
GB2467946B (en) * | 2009-02-20 | 2013-09-11 | Honeywell Uk Ltd | Air conditioning system |
DE102011110862A1 (en) * | 2011-08-17 | 2013-02-21 | Klingenburg Gmbh | Cooling device for outside air used to generate a supply air flow and method for cooling the same |
JP5814844B2 (en) * | 2012-03-26 | 2015-11-17 | 三菱電機株式会社 | Heat exchange ventilation system |
US20180372361A1 (en) * | 2015-12-22 | 2018-12-27 | Panasonic Intellectual Property Management Co., Ltd. | Heat exchange type ventilation device |
PL3717839T3 (en) * | 2017-11-30 | 2023-01-16 | Framatome Gmbh | Ventilation and air conditioning system with a passive emergency cooling mode |
RU203574U1 (en) * | 2020-03-10 | 2021-04-12 | Общество с ограниченной ответственностью "НТЦ Евровент" | Heat recovery device for industrial air conditioners for operation at low ambient temperatures |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
HU175359B (en) * | 1974-12-19 | 1980-07-28 | Epitestudomanyi Intezet | Air processor |
JPS5818566B2 (en) * | 1976-07-08 | 1983-04-13 | ダイキン工業株式会社 | heat recovery equipment |
CH660777A5 (en) * | 1983-08-16 | 1987-06-15 | Motor Columbus Ing | METHOD AND DEVICE FOR AIR-CONDITIONING ROOMS. |
US4910971A (en) * | 1988-02-05 | 1990-03-27 | Hydro Thermal Engineering Pty. Ltd. | Indirect air conditioning system |
SE8900848L (en) * | 1989-03-10 | 1990-09-11 | Sixten Persson | Air handling units |
FI88431C (en) * | 1989-08-22 | 1993-05-10 | Ilmateollisuus Oy | FOLLOWING OVERCHAIR FANGER |
FI92867C (en) * | 1991-11-22 | 1997-07-08 | Suomen Puhallintehdas Oy | Air conditioning equipment for rooms |
FI95505C (en) * | 1992-12-08 | 1996-02-12 | Flaekt Oy | Method and apparatus for air conditioning and heating of room spaces |
-
1995
- 1995-03-03 FI FI951011A patent/FI100132B/en active
-
1996
- 1996-03-01 DE DE19681367T patent/DE19681367T1/en not_active Withdrawn
- 1996-03-01 CA CA002214409A patent/CA2214409A1/en not_active Abandoned
- 1996-03-01 RU RU97116271/06A patent/RU2168116C2/en active
- 1996-03-01 WO PCT/FI1996/000123 patent/WO1996027767A1/en active Application Filing
-
1997
- 1997-09-02 SE SE9703156A patent/SE9703156L/en not_active Application Discontinuation
- 1997-09-02 NO NO974030A patent/NO974030L/en not_active Application Discontinuation
- 1997-09-03 DK DK100097A patent/DK100097A/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
WO1996027767A1 (en) | 1996-09-12 |
DE19681367T1 (en) | 1998-04-23 |
FI100132B (en) | 1997-09-30 |
FI951011A (en) | 1996-09-04 |
SE9703156L (en) | 1997-10-22 |
FI951011A0 (en) | 1995-03-03 |
RU2168116C2 (en) | 2001-05-27 |
DK100097A (en) | 1997-10-30 |
NO974030L (en) | 1997-10-31 |
NO974030D0 (en) | 1997-09-02 |
SE9703156D0 (en) | 1997-09-02 |
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