US20200370802A1 - Evaporator - Google Patents
Evaporator Download PDFInfo
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- US20200370802A1 US20200370802A1 US16/766,203 US201816766203A US2020370802A1 US 20200370802 A1 US20200370802 A1 US 20200370802A1 US 201816766203 A US201816766203 A US 201816766203A US 2020370802 A1 US2020370802 A1 US 2020370802A1
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- Prior art keywords
- tray
- exchanger tubes
- coolant fluid
- shell
- evaporator according
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Classifications
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- 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
- F25B39/00—Evaporators; Condensers
- F25B39/02—Evaporators
- F25B39/028—Evaporators having distributing means
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- 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
- F28D5/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation
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- 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
- F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
- F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
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- 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
- F25B2339/00—Details of evaporators; Details of condensers
- F25B2339/02—Details of evaporators
- F25B2339/024—Evaporators with refrigerant in a vessel in which is situated a heat exchanger
- F25B2339/0242—Evaporators with refrigerant in a vessel in which is situated a heat exchanger having tubular elements
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- 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
- F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
- F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
- F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
- F28D2021/0071—Evaporators
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- 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
- F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
- F28D21/0017—Flooded core heat exchangers
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- 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
- F28D5/00—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation
- F28D5/02—Heat-exchange apparatus having stationary conduit assemblies for one heat-exchange medium only, the media being in contact with different sides of the conduit wall, using the cooling effect of natural or forced evaporation in which the evaporating medium flows in a continuous film or trickles freely over the conduits
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
- F28F9/22—Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
- F28F2009/222—Particular guide plates, baffles or deflectors, e.g. having particular orientation relative to an elongated casing or conduit
- F28F2009/224—Longitudinal partitions
Definitions
- the present disclosure relates to an evaporator that is adapted to be used in refrigeration cycles based on the expansion of coolant gas, for conditioning and refrigeration applications.
- cooling apparatuses known as refrigerators or chillers
- refrigerators or chillers comprise, very basically, a compressor, an expansion device, an evaporator and a condenser.
- cooling apparatuses are in use which are constituted, in essence, by heat exchangers, which generally have a containment enclosure provided with a cylindrical shell which accommodates a tube bundle, which is composed of a plurality of exchanger tubes, and in which a first working fluid, which is constituted by a coolant fluid and is arranged outside exchanger tubes, evaporates, thus absorbing heat from a second working fluid, which is constituted typically by water or by an aqueous solution, which flows inside the exchanger tubes and which is thus cooled.
- heat exchangers which generally have a containment enclosure provided with a cylindrical shell which accommodates a tube bundle, which is composed of a plurality of exchanger tubes, and in which a first working fluid, which is constituted by a coolant fluid and is arranged outside exchanger tubes, evaporates, thus absorbing heat from a second working fluid, which is constituted typically by water or by an aqueous solution, which flows inside the exchanger tubes and which is thus cooled.
- the coolant fluid is fed from above by a dispenser so as to form, on the outer surface of the exchanger tubes, a film of coolant fluid which by gravity falls progressively downward, flowing along the outer surface of the exchanger tubes.
- the exchanger tubes are arranged inside a container which is designed to be flooded with the coolant in the liquid phase, so as to keep the exchanger tubes submerged in the coolant fluid, while this evaporates.
- a drawback of falling film evaporators is constituted by the fact that traditionally the dispenser of this type of evaporator works with a biphasic coolant fluid, i.e. made up of a liquid phase and a vapor phase, such that it is difficult to obtain a good distribution of the coolant fluid over the exchanger tubes.
- a drawback that is found with pool boiling evaporators derives from the fact that when the refrigerator works with a partial load, such that less thermal power needs to be exchanged, the level of coolant liquid inside the container of the evaporator generally decreases and some rows of exchanger tubes, arranged in the upper part, remain dry, or in a condition known in the jargon as “dry-out”. It is evident that under such operating conditions, which are the most common kind in a pool boiling evaporator, it is not possible to take full advantage of the heat exchange surface made available by the exchanger tubes.
- pool boiling evaporators Another disadvantage of pool boiling evaporators is that they require a considerable quantity of coolant liquid for their operation, which however contrasts with current environmental regulations which require the use of coolants that have a low environmental impact but which are high cost.
- hybrid evaporators have been proposed in which, in the upper part of the containment enclosure, the coolant liquid is deposited on the outer surface of some exchanger tubes of the tube bundle so as to form a film, so as to have an operation similar to that of falling film evaporators, while other exchanger tubes, located in the lower part of the enclosure, remain immersed in the coolant liquid, with an operation similar to that of pool boiling evaporators.
- Hybrid evaporators therefore have a clear separation between the part that is operating like a falling film evaporator and the part that is operating like a pool boiling evaporator, with the consequence that the advantages of one part do not make it possible to fully compensate the drawbacks of the other.
- each tray is supplied with the coolant liquid by way of a corresponding draining tube that originates from a dispenser arranged above the tube bundle or, according to another embodiment, exclusively by overflowing of the coolant liquid from the outer lateral edge of the immediately overlying tray.
- CN104819604 describes an evaporator with pool boiling operation, which is conceptually similar to what is described in CN2708220, with the difference that it has a dispenser that is rather complex in implementation, which is situated in a lateral region of the shell.
- CN104819604 there are again trays which are fed by overflowing the coolant liquid from the outer lateral edge of the overlying trays, and the possibility is not prevented of drawing the droplets of coolant liquid into the intake line of the compressor.
- CN205807912U also describes a pool boiling evaporator, similar to those of the prior art documents cited previously.
- the evaporator has a lateral shell containing a bundle of tubes which is divided into a plurality of layers, each one of which is arranged in a respective tray for collecting the coolant liquid, which falls by overflowing from one tray to the underlying tray, while the part of the coolant liquid that collects in the lower region of the shell is made to boil by exchanger tubes arranged on the bottom.
- the trays To enable each tray to collect the coolant liquid that overflows from the overlying tray, the trays have a lateral space occupation that progressively increases, going from the tray located highest toward the tray located lowest, with the consequence that the tube bundle has, in a plane perpendicular to the axis of the lateral wall, a triangular arrangement which however limits the maximum number of exchanger tubes that can be positioned inside the shell proper.
- US2008149311A1 then describes an evaporator that operates using the falling film method, in the upper part, and which has flat distribution units, provided with holes, which make it possible to evenly distribute the coolant liquid that drips onto the exchanger tubes.
- This evaporator too exhibits problems relating to the optimal distribution of the coolant liquid over the exchanger tubes, and offers no solution to the problem of drawing droplets of coolant liquid into the compressor.
- an evaporator that operates using the falling film method in the upper and central part of the lateral shell and using the pool boiling method in the lower part.
- the evaporator in this document has trays the purpose of which is to collect the coolant liquid in the lower part of the shell and to ensure, if there are compressors lubricated with oil, that the oil drains from the bottom.
- a deflector structure the purpose of which is to capture the droplets of coolant liquid contained in the coolant vapor, but which however extends only to the upper region of the evaporator, such that it is not capable of offering valid assurances of certainty of interception of the droplets of coolant liquid drawn from the vapor originating from all the exchanger tubes of the evaporator.
- the aim of the present disclosure is to provide an evaporator which is capable of improving the prior art in one or more of the above-mentioned aspects.
- the disclosure provides an evaporator that is capable of positively combining the advantages of pool boiling evaporators with those of falling film evaporators, without exhibiting the respective drawbacks.
- the disclosure further provides an evaporator that is capable of operating efficiently even under partial load conditions, by preventing situations in which the exchanger tubes end up in dry-out.
- the disclosure also provides an evaporator that makes it possible to prevent the drawing of droplets of coolant liquid toward the compressor.
- the disclosure further provides an evaporator that makes it possible to have an even distribution of the exchanger tubes inside the shell.
- the present disclosure overcomes the drawbacks of the prior art in an alternative manner to any existing solutions.
- the disclosure provides an evaporator that is highly reliable and which, furthermore, is easy to implement and at low cost.
- FIG. 1 is a perspective view of the evaporator according to the disclosure
- FIG. 2 is a perspective and longitudinal cross-sectional view of the evaporator according to the disclosure
- FIG. 3 is a perspective and longitudinal cross-sectional view of the evaporator according to the disclosure from which the shell, the dispenser and a shielding wall have been omitted, in order to better show the interior of the evaporator;
- FIG. 4 is a perspective view of the evaporator according to the disclosure with the shell omitted;
- FIG. 5 is a perspective view of a tray for collecting and distributing the cooling liquid belonging to the evaporator according to the disclosure with a row of exchanger tubes that are associated therewith;
- FIG. 6 is a perspective view of a tray of the evaporator according to the disclosure without the exchanger tubes;
- FIG. 7 is a longitudinal cross-sectional view of the evaporator according to the disclosure.
- FIG. 8 is a transverse cross-sectional view of a detail of the evaporator according to the disclosure.
- FIG. 9 is a perspective and longitudinal cross-sectional view of the dispenser of coolant fluid arranged inside of the evaporator according to the disclosure.
- FIG. 10 is a cross-sectional view of some exchanger tubes of the evaporator according to the disclosure.
- FIG. 11 is a transverse cross-sectional view of the evaporator according to the disclosure.
- FIG. 12 is a perspective and transverse cross-sectional view of the evaporator according to the disclosure.
- FIG. 13 is a perspective and transverse cross-sectional view from a different angle with respect to FIG. 12 of the evaporator according to the disclosure.
- FIG. 14 is a perspective view of different embodiment of the evaporator according to the disclosure, with several components omitted in order to show a first group of exchanger tubes and the corresponding trays;
- FIG. 15 is an enlarged-scale detail of FIG. 14 ;
- FIG. 16 is a schematic perspective view of a possible embodiment of the trays for collecting and distributing the liquid coolant fluid, in a condition of operation;
- FIG. 17 is a transverse cross-sectional view of the tray in FIG. 16 ;
- FIG. 18 is a schematic perspective view of the embodiment in FIG. 16 in a different condition of operation.
- FIG. 19 is a transverse cross-sectional view of the tray in FIG. 18 .
- the evaporator according to the disclosure generally designated by the reference numeral 1 , comprises an enclosure 2 which is provided with a lateral confinement shell 3 with a substantially horizontal axis, which internally defines a heat exchange chamber 3 a.
- a dispenser 4 Accommodated inside the shell 3 is a dispenser 4 , the function of which is to introduce a coolant fluid into the heat exchange chamber 3 a of the shell 3 , such fluid being fed to the dispenser 4 by way of a connector 5 passing through the shell 3 .
- the coolant fluid that is fed to the dispenser 4 is, generally, in a biphasic condition, i.e. it is made up of a liquid phase, hereinafter referred to as liquid coolant fluid, and by a vapor phase, hereinafter referred to as vapor of the coolant fluid.
- At least one tube bundle 6 which is arranged below the dispenser 4 and which comprises a plurality of exchanger tubes 7 , which extend substantially parallel to the axis of the shell 3 .
- the dispenser 4 comprises a distribution duct 4 a , which extends substantially parallel to the axis of the shell 3 and is connected to the connector 5 , by way of an own intake port 5 a , which is arranged substantially in a central position along its longitudinal extension.
- the distribution duct 4 a has a polygonal cross-section, with a flat lower wall 4 b which has a plurality of delivery openings 4 c from which the coolant fluid is drained downward in the direction of the tube bundle 6 .
- the exchanger tubes 7 are designed to be passed through by a fluid to be cooled, which is constituted, for example, by water or by an aqueous solution.
- the shell 3 is closed, at one end, by a first head 8 a , which is provided with an entry connection 9 a and with an exit connection 9 b for the fluid to be cooled, and, at its opposite end, by a second head 8 b .
- a first head 8 a and the second head and 8 b are channels 10 for the fluid to be cooled to circulate, which are connected to the inside of the exchanger tubes 7 , in order to allow the fluid to be cooled, once it is introduced into the shell 3 through the entry connection 9 a , to follow a path, inside the exchanger tubes 7 , with various passes along the longitudinal extension of the shell 3 , prior to exiting from the wall through the exit connection 9 b , as shown schematically in FIG. 7 .
- the tube bundle 6 comprises at least one first group of exchanger tubes 7 which is arranged along rows which extend on substantially horizontal and mutually superimposed planes.
- the exchanger tubes 7 of each one of these rows are arranged in at least one respective tray 11 , which is adapted to collect the liquid coolant fluid, so as to be able to keep the exchanger tubes 7 of each row at least partially immersed in the liquid coolant fluid, and to distribute it in the exchanger tubes 7 which are arranged in an underlying tray 11 .
- each tray 11 has, along at least one first longitudinal edge, at least one first containment sidewall 12 which is adapted to allow the liquid coolant fluid contained therein to fall by overflowing into an underlying tray 11 .
- each tray is furthermore provided in its bottom 11 a with a plurality of openings for draining 11 b the liquid coolant fluid, such holes being arranged at the exchanger tubes 7 contained in the underlying tray 11 in order to allow the fall of the liquid coolant fluid from each tray 11 onto the outer surface of the exchanger tubes 7 placed below it.
- each tray 11 is furthermore provided with a second containment sidewall 13 , which extends upward so as to contain, at least partially, the overlying tray 11 .
- second containment sidewall 13 is arranged along a second longitudinal edge of the tray 11 , opposite to the first longitudinal edge along which the first containment sidewall 12 is present.
- the second containment sidewall 13 has a portion, the extension of which is inclined toward the outside of the corresponding tray 11 , which conveniently is connected to a vertical portion that protrudes upward from the bottom 11 a of the tray 11 so as to create, between the second containment sidewall 13 of each tray 11 and the overlying tray 11 , a space for the outflow of the vapor produced by the boiling of the liquid coolant fluid contained in each tray 11 .
- the trays 11 in their succession along a vertical direction, the trays 11 present their first longitudinal edge, with the corresponding first containment sidewall 12 , alternately directed toward one side of the shell 3 or toward the opposite side.
- Such alternating arrangement, toward one side or the other of the shell 3 , of the first containment sidewall 12 of the various trays 11 allows an arrangement of the exchanger tubes 7 that is square or rectangular, when seen in transverse cross-section, with the consequence of enabling the positioning in the shell 3 of a greater number of exchanger tubes 7 with respect to triangular arrangements, as in the prior art.
- the trays 11 have the corresponding first containment sidewall 12 arranged laterally spaced apart toward the inside of the shell 3 with respect to the second confinement sidewall 13 of the underlying tray 11 , so that the liquid coolant fluid overflowing from each tray 11 over the corresponding first containment sidewall 12 can fall, without losses, into the underlying tray 11 .
- the openings for draining 11 b defined in the bottom 11 a of the trays 11 have a size that is calibrated to balance the quantity of liquid coolant fluid that enters each tray 11 with the quantity of coolant fluid that exits in vapor form from each tray 11 .
- equal importance lies with the total passage section made available for the liquid coolant fluid by the set of the openings for draining 11 b , in combination with the size of each one of these openings.
- the size of the openings for draining 11 b can be the same for all the trays 11 or different from tray to tray.
- the sizes of the openings for draining 11 b can conveniently vary substantially from 1 mm to 20 mm.
- the size of the openings for draining 11 b to progressively decrease starting from the tray 11 located highest and proceeding progressively toward the tray located lowest.
- each tray 11 provides means of flow control which are adapted to at least partially block the openings for draining 11 b and can move on command in order to vary the degree of opening of the openings for draining 11 b .
- means of flow control can comprise, for each tray 11 , a plate 110 which is provided with passage openings 111 , which have, conveniently, a size and an arrangement that are substantially the same as the openings for draining 11 b .
- the plate 110 is slideably mounted with respect to the bottom 11 a of the respective tray 11 in order to pass from a first condition, shown in FIGS.
- each tray 11 is stacked by interlocking on the underlying tray 11 , advantageously without requiring welding or other types of fixing, so as to provide a supporting structure capable of supporting at least the exchanger tubes 7 of the first group.
- the trays 11 are arranged alternately staggered toward one side or toward the other side of the shell 3 , so as to create between each tray 11 and the overlying tray the space for the passage of the liquid coolant fluid overflowing over the first confinement sidewall 12 of the overlying tray and for the egress from each tray 11 of the vapor of the coolant fluid.
- each tray 11 at its longitudinal ends, arranged along its axis of extension parallel to the axis of the shell 3 , is provided, advantageously, with containment end walls 14 which define receptacles 15 for the respective exchanger tubes 7 , which are constituted by holes that are passed through hermetically by the exchanger tubes 7 , so that each tray 11 can also act as a support per the corresponding exchanger tubes 7 .
- the trays 11 are provided with the same shape and each one is arranged rotated by 180° about a vertical axis with respect to the two contiguous ones, in succession along the direction of stacking, so as to alternately present the first containment sidewall 12 toward one side or toward the other side of the shell 3 .
- each tray 11 is provided with at least one supporting partition 16 for the overlying tray 11 .
- each tray 11 has a pair of supporting partitions 16 , which are arranged at its opposing longitudinal ends and are preferably defined continuously with the containment end walls 14 . Each one of such supporting partitions 16 protrudes laterally outward with respect to the first confinement sidewall 12 of each tray 11 .
- such supporting partitions 16 define a positioning abutment for the tray 11 stacked on top of the corresponding tray 11 .
- the supporting partitions 16 define, in a position laterally spaced apart and outward with respect to the first containment sidewall 12 of the corresponding tray 11 , at least one lateral abutment shoulder 16 a , on which the second confinement sidewall 13 of the tray 11 stacked above is placed, so as to ensure the arrangement in a mutually spaced apart position between the first confinement sidewall 12 of each tray 11 and the second confinement sidewall 13 of the underlying tray.
- the vapor produced by the boiling of the liquid coolant fluid is conveyed outside the shell 3 by way of an exit connector 17 defined in the upper part of the shell 3 .
- At least one shielding wall 18 inside the shell 3 and laterally to the tube bundle 6 , there is at least one shielding wall 18 , which makes it possible to prevent the egress, by way of an exit connector 17 , of droplets of liquid together with the vapor of the coolant fluid.
- the shielding wall 18 extends downward, with two portions that are mutually opposite with respect to the tube bundle 6 , and defines, for the vapor of the coolant fluid exiting from the trays 11 , at least one respective first flow channel 18 a and at least one respective second flow channel 18 b .
- the first flow channel 18 a extends downward and is delimited between the tube bundle 6 and the shielding wall 18
- the second flow channel 18 b extends upward and is delimited between the shell 3 and the shielding wall 18 .
- the fluid to be cooled is made to enter the shell 3 , through the entry connection 9 a , so that it can run through the exchanger tubes 7 until it arrives at the exit connection as shown in FIG. 7 , where arrows show the possible path of the fluid to be cooled.
- the coolant fluid coming into contact with the exchanger tubes 7 passed through by the fluid to be cooled, starts to evaporate and the two phases, vapor and liquid, of the coolant fluid separate, following different paths.
- the liquid coolant fluid which does not evaporate, falls onto the row of exchanger tubes 7 arranged in the second tray 11 , arranged below the first tray 11 , in two possible ways: either by overflowing over the first confinement sidewall 12 or by passing through the openings for draining 11 b.
- the disclosure fully achieves the intended aim and objects, in that, by virtue of the presence of the trays provided with openings for draining and the possibility for the coolant liquid to overflow from them, it makes it possible to take better advantage of the exchange surface of the exchanger tubes with respect to a traditional falling film evaporator, and, by virtue of the openings for draining arranged on the bottom of the trays, it makes it possible to prevent, under partial load conditions, some rows of exchanger tubes from remaining dry, with a consequent improvement of the wettability of the exchanger tubes with respect to a traditional pool boiling evaporator as well.
- Another advantage of the evaporator according to the disclosure is that it enables a reduction of the quantity of coolant required with respect to a pool boiling evaporator.
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- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
An evaporator includes an enclosure with a lateral confinement shell with a substantially horizontal axis, which internally accommodates a dispenser of a coolant fluid and at least one tube bundle, which is arranged below the dispenser. The evaporator further includes exchanger tubes, which are passed through by a fluid to be cooled. At least one first group of exchanger tubes is arranged along rows which extend on substantially horizontal and mutually superimposed planes. The exchanger tubes of each row are arranged in at least one respective tray for collecting and distributing the liquid coolant fluid. Each tray has, along at least one first longitudinal edge, at least one first containment sidewall which is adapted to allow the liquid coolant fluid contained therein to fall by overflowing into an underlying tray and is provided in its bottom with openings for draining the liquid coolant fluid.
Description
- The present disclosure relates to an evaporator that is adapted to be used in refrigeration cycles based on the expansion of coolant gas, for conditioning and refrigeration applications.
- As is known, cooling apparatuses, known as refrigerators or chillers, comprise, very basically, a compressor, an expansion device, an evaporator and a condenser.
- In particular, in cooling apparatuses evaporators are in use which are constituted, in essence, by heat exchangers, which generally have a containment enclosure provided with a cylindrical shell which accommodates a tube bundle, which is composed of a plurality of exchanger tubes, and in which a first working fluid, which is constituted by a coolant fluid and is arranged outside exchanger tubes, evaporates, thus absorbing heat from a second working fluid, which is constituted typically by water or by an aqueous solution, which flows inside the exchanger tubes and which is thus cooled.
- Two types of evaporators are known: falling film evaporators and pool boiling evaporators.
- In falling film evaporators, the coolant fluid is fed from above by a dispenser so as to form, on the outer surface of the exchanger tubes, a film of coolant fluid which by gravity falls progressively downward, flowing along the outer surface of the exchanger tubes.
- In a pool boiling evaporator, instead, the exchanger tubes are arranged inside a container which is designed to be flooded with the coolant in the liquid phase, so as to keep the exchanger tubes submerged in the coolant fluid, while this evaporates.
- A drawback of falling film evaporators is constituted by the fact that traditionally the dispenser of this type of evaporator works with a biphasic coolant fluid, i.e. made up of a liquid phase and a vapor phase, such that it is difficult to obtain a good distribution of the coolant fluid over the exchanger tubes.
- A drawback that is found with pool boiling evaporators derives from the fact that when the refrigerator works with a partial load, such that less thermal power needs to be exchanged, the level of coolant liquid inside the container of the evaporator generally decreases and some rows of exchanger tubes, arranged in the upper part, remain dry, or in a condition known in the jargon as “dry-out”. It is evident that under such operating conditions, which are the most common kind in a pool boiling evaporator, it is not possible to take full advantage of the heat exchange surface made available by the exchanger tubes.
- Another disadvantage of pool boiling evaporators is that they require a considerable quantity of coolant liquid for their operation, which however contrasts with current environmental regulations which require the use of coolants that have a low environmental impact but which are high cost.
- In an attempt to overcome these and other drawbacks, hybrid evaporators have been proposed in which, in the upper part of the containment enclosure, the coolant liquid is deposited on the outer surface of some exchanger tubes of the tube bundle so as to form a film, so as to have an operation similar to that of falling film evaporators, while other exchanger tubes, located in the lower part of the enclosure, remain immersed in the coolant liquid, with an operation similar to that of pool boiling evaporators.
- Hybrid evaporators therefore have a clear separation between the part that is operating like a falling film evaporator and the part that is operating like a pool boiling evaporator, with the consequence that the advantages of one part do not make it possible to fully compensate the drawbacks of the other.
- From CN2708220 an evaporator is known with pool boiling operation which is used in absorption systems and which has a plurality of trays for collecting the coolant liquid, each one of which is arranged below a respective horizontal row of exchanger tubes, so that the exchanger tubes are partially immersed in the coolant liquid gathered in the respective tray. In such prior art document, each tray is supplied with the coolant liquid by way of a corresponding draining tube that originates from a dispenser arranged above the tube bundle or, according to another embodiment, exclusively by overflowing of the coolant liquid from the outer lateral edge of the immediately overlying tray. This solution makes it possible to reduce the quantity of coolant liquid required and to avoid the use of a recirculation pump. However, feeding the trays exclusively by virtue of the overflow of the coolant liquid is not efficient, in that it risks the trays in the lower part of the evaporator not receiving coolant liquid, thus leaving the corresponding exchanger tubes in dry-out. Furthermore, in the evaporator in CN2708220 the possibility is not prevented that droplets of coolant liquid drawn from the vapor of the coolant originating from the trays arranged higher up inside the shell of the evaporator could reach the compressor of the cooling apparatus, with the consequent risk of compromising the operation of the compressor.
- CN104819604 describes an evaporator with pool boiling operation, which is conceptually similar to what is described in CN2708220, with the difference that it has a dispenser that is rather complex in implementation, which is situated in a lateral region of the shell. In CN104819604, there are again trays which are fed by overflowing the coolant liquid from the outer lateral edge of the overlying trays, and the possibility is not prevented of drawing the droplets of coolant liquid into the intake line of the compressor.
- CN205807912U also describes a pool boiling evaporator, similar to those of the prior art documents cited previously. In particular, in this prior art document, the evaporator has a lateral shell containing a bundle of tubes which is divided into a plurality of layers, each one of which is arranged in a respective tray for collecting the coolant liquid, which falls by overflowing from one tray to the underlying tray, while the part of the coolant liquid that collects in the lower region of the shell is made to boil by exchanger tubes arranged on the bottom. To enable each tray to collect the coolant liquid that overflows from the overlying tray, the trays have a lateral space occupation that progressively increases, going from the tray located highest toward the tray located lowest, with the consequence that the tube bundle has, in a plane perpendicular to the axis of the lateral wall, a triangular arrangement which however limits the maximum number of exchanger tubes that can be positioned inside the shell proper.
- Furthermore, even in CN205807912U, there is no solution to the problem of drawing droplets of coolant liquid toward the compressor.
- US2008149311A1 then describes an evaporator that operates using the falling film method, in the upper part, and which has flat distribution units, provided with holes, which make it possible to evenly distribute the coolant liquid that drips onto the exchanger tubes. This evaporator too exhibits problems relating to the optimal distribution of the coolant liquid over the exchanger tubes, and offers no solution to the problem of drawing droplets of coolant liquid into the compressor.
- In US2015013951, an evaporator is described that operates using the falling film method in the upper and central part of the lateral shell and using the pool boiling method in the lower part. The evaporator in this document has trays the purpose of which is to collect the coolant liquid in the lower part of the shell and to ensure, if there are compressors lubricated with oil, that the oil drains from the bottom. In such document, furthermore, above the tube bundle there is a deflector structure, the purpose of which is to capture the droplets of coolant liquid contained in the coolant vapor, but which however extends only to the upper region of the evaporator, such that it is not capable of offering valid assurances of certainty of interception of the droplets of coolant liquid drawn from the vapor originating from all the exchanger tubes of the evaporator.
- The aim of the present disclosure is to provide an evaporator which is capable of improving the prior art in one or more of the above-mentioned aspects.
- Within this aim, the disclosure provides an evaporator that is capable of positively combining the advantages of pool boiling evaporators with those of falling film evaporators, without exhibiting the respective drawbacks.
- The disclosure further provides an evaporator that is capable of operating efficiently even under partial load conditions, by preventing situations in which the exchanger tubes end up in dry-out.
- The disclosure also provides an evaporator that makes it possible to prevent the drawing of droplets of coolant liquid toward the compressor.
- The disclosure further provides an evaporator that makes it possible to have an even distribution of the exchanger tubes inside the shell.
- Furthermore, the present disclosure overcomes the drawbacks of the prior art in an alternative manner to any existing solutions.
- The disclosure provides an evaporator that is highly reliable and which, furthermore, is easy to implement and at low cost.
- This aim and these and other advantages which will become better apparent hereinafter are achieved by providing an evaporator according to
claim 1, optionally provided with one or more of the characteristics of the dependent claims. - Further characteristics and advantages of the disclosure will become better apparent from the description of some preferred, but not exclusive, embodiments of the evaporator according to the disclosure, which are illustrated for the purposes of non-limiting example in the accompanying drawings wherein:
-
FIG. 1 is a perspective view of the evaporator according to the disclosure; -
FIG. 2 is a perspective and longitudinal cross-sectional view of the evaporator according to the disclosure; -
FIG. 3 is a perspective and longitudinal cross-sectional view of the evaporator according to the disclosure from which the shell, the dispenser and a shielding wall have been omitted, in order to better show the interior of the evaporator; -
FIG. 4 is a perspective view of the evaporator according to the disclosure with the shell omitted; -
FIG. 5 is a perspective view of a tray for collecting and distributing the cooling liquid belonging to the evaporator according to the disclosure with a row of exchanger tubes that are associated therewith; -
FIG. 6 is a perspective view of a tray of the evaporator according to the disclosure without the exchanger tubes; -
FIG. 7 is a longitudinal cross-sectional view of the evaporator according to the disclosure; -
FIG. 8 is a transverse cross-sectional view of a detail of the evaporator according to the disclosure; -
FIG. 9 is a perspective and longitudinal cross-sectional view of the dispenser of coolant fluid arranged inside of the evaporator according to the disclosure; -
FIG. 10 is a cross-sectional view of some exchanger tubes of the evaporator according to the disclosure; -
FIG. 11 is a transverse cross-sectional view of the evaporator according to the disclosure; -
FIG. 12 is a perspective and transverse cross-sectional view of the evaporator according to the disclosure; -
FIG. 13 is a perspective and transverse cross-sectional view from a different angle with respect toFIG. 12 of the evaporator according to the disclosure; -
FIG. 14 is a perspective view of different embodiment of the evaporator according to the disclosure, with several components omitted in order to show a first group of exchanger tubes and the corresponding trays; and -
FIG. 15 is an enlarged-scale detail ofFIG. 14 ; -
FIG. 16 is a schematic perspective view of a possible embodiment of the trays for collecting and distributing the liquid coolant fluid, in a condition of operation; -
FIG. 17 is a transverse cross-sectional view of the tray inFIG. 16 ; -
FIG. 18 is a schematic perspective view of the embodiment inFIG. 16 in a different condition of operation; and -
FIG. 19 is a transverse cross-sectional view of the tray inFIG. 18 . - With reference to the figures, the evaporator according to the disclosure, generally designated by the
reference numeral 1, comprises anenclosure 2 which is provided with alateral confinement shell 3 with a substantially horizontal axis, which internally defines aheat exchange chamber 3 a. - Accommodated inside the
shell 3 is adispenser 4, the function of which is to introduce a coolant fluid into theheat exchange chamber 3 a of theshell 3, such fluid being fed to thedispenser 4 by way of aconnector 5 passing through theshell 3. It should be noted that the coolant fluid that is fed to thedispenser 4 is, generally, in a biphasic condition, i.e. it is made up of a liquid phase, hereinafter referred to as liquid coolant fluid, and by a vapor phase, hereinafter referred to as vapor of the coolant fluid. - Also accommodated inside the
shell 3 is at least onetube bundle 6, which is arranged below thedispenser 4 and which comprises a plurality ofexchanger tubes 7, which extend substantially parallel to the axis of theshell 3. - For example, the
dispenser 4 comprises adistribution duct 4 a, which extends substantially parallel to the axis of theshell 3 and is connected to theconnector 5, by way of anown intake port 5 a, which is arranged substantially in a central position along its longitudinal extension. Conveniently, thedistribution duct 4 a has a polygonal cross-section, with a flatlower wall 4 b which has a plurality ofdelivery openings 4 c from which the coolant fluid is drained downward in the direction of thetube bundle 6. - The
exchanger tubes 7 are designed to be passed through by a fluid to be cooled, which is constituted, for example, by water or by an aqueous solution. - Conveniently, the
shell 3 is closed, at one end, by afirst head 8 a, which is provided with anentry connection 9 a and with anexit connection 9 b for the fluid to be cooled, and, at its opposite end, by asecond head 8 b. Defined inside thefirst head 8 a and the second head and 8 b arechannels 10 for the fluid to be cooled to circulate, which are connected to the inside of theexchanger tubes 7, in order to allow the fluid to be cooled, once it is introduced into theshell 3 through theentry connection 9 a, to follow a path, inside theexchanger tubes 7, with various passes along the longitudinal extension of theshell 3, prior to exiting from the wall through theexit connection 9 b, as shown schematically inFIG. 7 . - Also inside the
shell 3 there is a plurality oftrays 11 for collecting and distributing the liquid coolant fluid, at least some of which are arranged one over the other. - In more detail, the
tube bundle 6 comprises at least one first group ofexchanger tubes 7 which is arranged along rows which extend on substantially horizontal and mutually superimposed planes. - In particular, the
exchanger tubes 7 of each one of these rows are arranged in at least onerespective tray 11, which is adapted to collect the liquid coolant fluid, so as to be able to keep theexchanger tubes 7 of each row at least partially immersed in the liquid coolant fluid, and to distribute it in theexchanger tubes 7 which are arranged in anunderlying tray 11. - More specifically, according to the disclosure, each
tray 11 has, along at least one first longitudinal edge, at least onefirst containment sidewall 12 which is adapted to allow the liquid coolant fluid contained therein to fall by overflowing into anunderlying tray 11. - Also according to the disclosure, each tray is furthermore provided in its bottom 11 a with a plurality of openings for draining 11 b the liquid coolant fluid, such holes being arranged at the
exchanger tubes 7 contained in theunderlying tray 11 in order to allow the fall of the liquid coolant fluid from eachtray 11 onto the outer surface of theexchanger tubes 7 placed below it. - In this manner, an optimal distribution is ensured of the liquid coolant fluid onto the
exchanger tubes 7 in that the liquid coolant fluid is supplied around theexchanger tubes 7 in two ways i.e. not only by way of its falling by overflowing over the side of the overlyingtray 11 but also by way of its falling through the openings for draining 11 b of the overlyingtray 11. - Advantageously, each
tray 11 is furthermore provided with asecond containment sidewall 13, which extends upward so as to contain, at least partially, the overlyingtray 11. Conveniently, suchsecond containment sidewall 13 is arranged along a second longitudinal edge of thetray 11, opposite to the first longitudinal edge along which thefirst containment sidewall 12 is present. - Advantageously, the
second containment sidewall 13 has a portion, the extension of which is inclined toward the outside of the correspondingtray 11, which conveniently is connected to a vertical portion that protrudes upward from the bottom 11 a of thetray 11 so as to create, between thesecond containment sidewall 13 of eachtray 11 and the overlyingtray 11, a space for the outflow of the vapor produced by the boiling of the liquid coolant fluid contained in eachtray 11. - It should be noted that in the figures and, in particular, in
FIGS. 8, 10 and 11 , the path of the liquid coolant fluid inside theshell 3 is indicated with arrows with dotted lines, while the path of the vapor of the coolant fluid is indicated with arrows with continuous lines. - Conveniently, in their succession along a vertical direction, the
trays 11 present their first longitudinal edge, with the correspondingfirst containment sidewall 12, alternately directed toward one side of theshell 3 or toward the opposite side. - Such alternating arrangement, toward one side or the other of the
shell 3, of thefirst containment sidewall 12 of thevarious trays 11 allows an arrangement of theexchanger tubes 7 that is square or rectangular, when seen in transverse cross-section, with the consequence of enabling the positioning in theshell 3 of a greater number ofexchanger tubes 7 with respect to triangular arrangements, as in the prior art. - It should be furthermore noted that, in their mutual arrangement, the
trays 11 have the correspondingfirst containment sidewall 12 arranged laterally spaced apart toward the inside of theshell 3 with respect to thesecond confinement sidewall 13 of theunderlying tray 11, so that the liquid coolant fluid overflowing from eachtray 11 over the correspondingfirst containment sidewall 12 can fall, without losses, into theunderlying tray 11. - Conveniently, the openings for draining 11 b defined in the bottom 11 a of the
trays 11 have a size that is calibrated to balance the quantity of liquid coolant fluid that enters eachtray 11 with the quantity of coolant fluid that exits in vapor form from eachtray 11. To this end, equal importance lies with the total passage section made available for the liquid coolant fluid by the set of the openings for draining 11 b, in combination with the size of each one of these openings. - In this manner, the heat exchange is ensured between the
exchanger tubes 7 and the liquid coolant fluid according to a method typical of evaporators of the film falling type, and a supply to the underlying trays is ensured even when operating under a partial load. - Advantageously, the size of the openings for draining 11 b can be the same for all the
trays 11 or different from tray to tray. In particular, the sizes of the openings for draining 11 b can conveniently vary substantially from 1 mm to 20 mm. - For example, it is possible for the size of the openings for draining 11 b to progressively decrease starting from the
tray 11 located highest and proceeding progressively toward the tray located lowest. - It is also possible for each
tray 11 to provide means of flow control which are adapted to at least partially block the openings for draining 11 b and can move on command in order to vary the degree of opening of the openings for draining 11 b. For example, such means of flow control can comprise, for eachtray 11, aplate 110 which is provided withpassage openings 111, which have, conveniently, a size and an arrangement that are substantially the same as the openings for draining 11 b. In particular, theplate 110 is slideably mounted with respect to the bottom 11 a of therespective tray 11 in order to pass from a first condition, shown inFIGS. 18 and 19 , in which itspassage openings 111 are arranged in alignment with the openings for draining 11 b of the correspondingtray 11, to at least one second condition, shown inFIGS. 16 and 17 , in which theplate 110 at least partially occludes the openings for draining 11 b of the correspondingtray 11 b, and vice versa. - According to the preferred embodiment, each
tray 11 is stacked by interlocking on theunderlying tray 11, advantageously without requiring welding or other types of fixing, so as to provide a supporting structure capable of supporting at least theexchanger tubes 7 of the first group. - Conveniently, the
trays 11 are arranged alternately staggered toward one side or toward the other side of theshell 3, so as to create between eachtray 11 and the overlying tray the space for the passage of the liquid coolant fluid overflowing over thefirst confinement sidewall 12 of the overlying tray and for the egress from eachtray 11 of the vapor of the coolant fluid. - In greater detail, as shown in
FIGS. 5 and 6 , eachtray 11, at its longitudinal ends, arranged along its axis of extension parallel to the axis of theshell 3, is provided, advantageously, withcontainment end walls 14 which definereceptacles 15 for therespective exchanger tubes 7, which are constituted by holes that are passed through hermetically by theexchanger tubes 7, so that eachtray 11 can also act as a support per the correspondingexchanger tubes 7. - Advantageously, the
trays 11 are provided with the same shape and each one is arranged rotated by 180° about a vertical axis with respect to the two contiguous ones, in succession along the direction of stacking, so as to alternately present thefirst containment sidewall 12 toward one side or toward the other side of theshell 3. - In more detail, each
tray 11 is provided with at least one supportingpartition 16 for the overlyingtray 11. - More preferably, each
tray 11 has a pair of supportingpartitions 16, which are arranged at its opposing longitudinal ends and are preferably defined continuously with thecontainment end walls 14. Each one of such supportingpartitions 16 protrudes laterally outward with respect to thefirst confinement sidewall 12 of eachtray 11. - Conveniently, in their upper part, such supporting
partitions 16 define a positioning abutment for thetray 11 stacked on top of the correspondingtray 11. In particular, the supportingpartitions 16 define, in a position laterally spaced apart and outward with respect to thefirst containment sidewall 12 of the correspondingtray 11, at least onelateral abutment shoulder 16 a, on which thesecond confinement sidewall 13 of thetray 11 stacked above is placed, so as to ensure the arrangement in a mutually spaced apart position between thefirst confinement sidewall 12 of eachtray 11 and thesecond confinement sidewall 13 of the underlying tray. - The vapor produced by the boiling of the liquid coolant fluid is conveyed outside the
shell 3 by way of anexit connector 17 defined in the upper part of theshell 3. - Advantageously, inside the
shell 3 and laterally to thetube bundle 6, there is at least one shieldingwall 18, which makes it possible to prevent the egress, by way of anexit connector 17, of droplets of liquid together with the vapor of the coolant fluid. - Preferably, the shielding
wall 18 extends downward, with two portions that are mutually opposite with respect to thetube bundle 6, and defines, for the vapor of the coolant fluid exiting from thetrays 11, at least one respectivefirst flow channel 18 a and at least one respectivesecond flow channel 18 b. In particular, thefirst flow channel 18 a extends downward and is delimited between thetube bundle 6 and the shieldingwall 18, while thesecond flow channel 18 b extends upward and is delimited between theshell 3 and the shieldingwall 18. - Conveniently, the shielding wall is arc-shaped with the concavity directed toward the
tube bundle 6 so as to cover the upper part thereof and at least partially the lateral part thereof and is passed through by theintake port 5 a of thedistribution duct 4 a. Conveniently, the shieldingwall 18 is supported at its longitudinal ends by a pair oftuyere plates shell 3 is interposed and to which theheads shell 3. - Advantageously, below the first group of
exchanger tubes 7 i.e. theexchanger tubes 7 arranged in thetrays 11, there can also be a second group ofexchanger tubes 7, proximate to the bottom of theshell 3, which are designed to evaporate the excess liquid coolant fluid that collects in the lower part of theshell 3. In this manner, there is no need to install a pump or an ejection system to make the liquid coolant fluid recirculate from the bottom of the shell to theconnector 5. - It should be added that it is also possible to arrange two or
more trays 11 arranged mutually laterally adjacent on respective horizontal levels in order to accommodate the same row ofexchanger tubes 7, if it is intended to useexchanger tubes 7 that are longer than the longitudinal extension of thesingle trays 11, as shown in particular inFIGS. 14 and 15 . - For the sake of completeness it should be added that in the lower part of the
shell 3, preferably below the second group ofexchanger tubes 7, there is, advantageously, at least onedischarge outlet 20, which is provided, conveniently, with an adaptedconnector 21, in order to allow, in the eventuality that the evaporator is used in refrigeration systems in which oil-lubricated compressors are used, the extraction from theshell 3 of the oil originating from the compressor, so as to permit the return of same to the compressor. - Operation of the evaporator, according to the disclosure, is the following.
- The coolant fluid, generally in the form of a biphasic mixture composed of a liquid phase and a vapor phase, enters, from the upper part of the
shell 3, through theconnector 5, into thedispenser 4, feeding thedistribution duct 4 a, from which it exits, through thedelivery openings 4 c, so as to be evenly distributed in thefirst tray 11 which is arranged higher than the others. - The fluid to be cooled is made to enter the
shell 3, through theentry connection 9 a, so that it can run through theexchanger tubes 7 until it arrives at the exit connection as shown inFIG. 7 , where arrows show the possible path of the fluid to be cooled. - In the
first tray 11, the coolant fluid, coming into contact with theexchanger tubes 7 passed through by the fluid to be cooled, starts to evaporate and the two phases, vapor and liquid, of the coolant fluid separate, following different paths. - The liquid coolant fluid, which does not evaporate, falls onto the row of
exchanger tubes 7 arranged in thesecond tray 11, arranged below thefirst tray 11, in two possible ways: either by overflowing over thefirst confinement sidewall 12 or by passing through the openings for draining 11 b. - In particular, when the level of liquid coolant fluid in the
first tray 11 exceeds the height of thefirst confinement sidewall 12, a part of the liquid coolant fluid falls into thesecond tray 11 by overflowing, while another part of the liquid coolant fluid can fall at eachexchanger tube 7 of the underlying row arranged in thesecond tray 11, through the openings for draining 11 b arranged on the bottom 11 a of thefirst tray 11, as shown inFIG. 8 , with a falling film operating method. - If, under partial load conditions, the level of liquid coolant fluid drops below the height of the
first confinement sidewall 12, supply of theunderlying tray 11 and therefore the wettability of thelower exchanger tubes 7 is still ensured by the openings for draining 11 b. - In the same way, all the
other trays 11 are progressively supplied, as shown inFIG. 10 . - The coolant fluid that evaporates exits from the lateral parts of the
trays 11 and, as shown inFIG. 11 , is channeled into thefirst flow channels 18 a, defined between thetube bundle 6 and the shieldingwall 18, and, subsequently, into thesecond flow channels 18 b, defined between the shieldingwall 18 and theshell 3, before arriving at the top of theshell 3, from which it exits by way of theexit connector 17. - The liquid coolant fluid gathered in the bottom of the
shell 3 is made to evaporate by theexchanger tubes 7 of the second group, with a pool boiling operating method. - In practice it has been found that the disclosure fully achieves the intended aim and objects, in that, by virtue of the presence of the trays provided with openings for draining and the possibility for the coolant liquid to overflow from them, it makes it possible to take better advantage of the exchange surface of the exchanger tubes with respect to a traditional falling film evaporator, and, by virtue of the openings for draining arranged on the bottom of the trays, it makes it possible to prevent, under partial load conditions, some rows of exchanger tubes from remaining dry, with a consequent improvement of the wettability of the exchanger tubes with respect to a traditional pool boiling evaporator as well.
- Another advantage of the evaporator according to the disclosure is that it enables a reduction of the quantity of coolant required with respect to a pool boiling evaporator.
- The disclosure, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.
- In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.
- The disclosures in Italian Patent Application No. 102017000136156 from which this application claims priority are incorporated herein by reference.
Claims (15)
1-14. (canceled)
15. An evaporator comprising: an enclosure having a lateral confinement shell with a substantially horizontal axis, which internally accommodates a dispenser of a liquid coolant fluid and at least one tube bundle, which is arranged below said dispenser and comprises a plurality of exchanger tubes which extend substantially parallel to the axis of said shell and are configured to be passed through by a fluid to be cooled, at least one first group of said exchanger tubes being arranged along rows which extend on substantially horizontal and mutually superimposed planes, wherein the exchanger tubes of each one of said rows are arranged in at least one respective tray, which is adapted to collect the liquid coolant fluid in order to keep the exchanger tubes of each one of said rows at least partially immersed in said liquid coolant fluid, each one of the trays having, along at least one first longitudinal edge, at least one first containment sidewall which is adapted to allow the liquid coolant fluid contained therein to fall by overflowing into an underlying tray and is provided in its bottom with a plurality of openings for draining the liquid coolant fluid, which are arranged at the exchanger tubes of the underlying tray in order to allow the liquid coolant fluid to fall from each tray onto the outer surface of the exchanger tubes of the underlying tray.
16. The evaporator according to claim 15 , wherein each tray is provided with a second containment sidewall which extends upward to contain at least partially the overlying tray.
17. The evaporator according to claim 16 , wherein said second containment sidewall is arranged along a second longitudinal edge of the corresponding tray which lies opposite with respect to said first longitudinal edge.
18. The evaporator according to claim 16 , wherein said second containment sidewall has a portion having an extension inclined towards the outside of the corresponding tray.
19. The evaporator according to claim 15 , wherein said trays have, in mutual alternation, in succession, said first longitudinal edge directed towards one side of said shell or towards the opposite side.
20. The evaporator according to claim 15 , wherein said openings for draining have a size that is calibrated to balance a quantity of liquid coolant fluid that enters each tray with a quantity of coolant fluid that exits in vapor form from each tray.
21. The evaporator according to claim 15 , wherein a size of said openings for draining is different from tray to tray.
22. The evaporator according to claim 15 , further comprising, for each tray, means of flow control configured to move on command and adapted to affect at least partially said openings for draining.
23. The evaporator according to claim 15 , wherein each tray is mounted stacked by interlocking on an underlying tray to provide a load-bearing structure for at least the exchanger tubes of said first group of exchanger tubes.
24. The evaporator according to claim 15 , wherein each tray has at least one supporting partition which defines at least one positioning abutment for an overlying tray.
25. The evaporator according to claim 15 , wherein each tray has, at first and second tray ends arranged along its longitudinal axis that is parallel to the axis of said shell, containment end walls which define receptacles for the respective exchanger tubes.
26. The evaporator according to claim 15 , further comprising, at least one shielding wall disposed inside said shell and laterally to said tube bundle, said at least one shielding wall extends downward and defines, for the vapor of said coolant fluid that exits from said trays, at least one first flow channel which extends downward and is delimited between said tube bundle and said at least one shielding wall and at least one second flow channel which extends upward and is delimited between said shell and said shielding wall.
27. The evaporator according to claim 15 , further comprising a second group of exchanger tubes disposed below said first group of exchanger tubes, said second group of exchanger tubes is configured to cause the evaporation of the excess liquid coolant fluid collected in the lower part of said shell.
28. The evaporator according to claim 15 , wherein at least one discharge outlet configured for the extraction of oil is disposed in a lower part of said shell.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT102017000136156 | 2017-11-28 | ||
IT201700136156 | 2017-11-28 | ||
PCT/EP2018/071947 WO2019105607A1 (en) | 2017-11-28 | 2018-08-13 | Evaporator |
Publications (1)
Publication Number | Publication Date |
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US20200370802A1 true US20200370802A1 (en) | 2020-11-26 |
Family
ID=61581526
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/766,203 Abandoned US20200370802A1 (en) | 2017-11-28 | 2018-08-13 | Evaporator |
Country Status (3)
Country | Link |
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US (1) | US20200370802A1 (en) |
EP (1) | EP3717843B1 (en) |
WO (1) | WO2019105607A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11619428B2 (en) * | 2018-04-06 | 2023-04-04 | Carrier Corporation | Integrated separator and distributor |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3097307B1 (en) * | 2019-06-17 | 2021-05-14 | Naval Energies | Evaporator of a working fluid for an ETM plant comprising a cover |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3124796A1 (en) * | 1981-06-24 | 1983-01-13 | Brown, Boveri & Cie Ag, 6800 Mannheim | Heat exchanger for an absorption refrigeration or heat pump system |
JPS61125588A (en) * | 1984-11-22 | 1986-06-13 | Toshiba Corp | Flow-down liquid film evaporating type heat exchanger |
JP2004176969A (en) * | 2002-11-26 | 2004-06-24 | Kubota Corp | Absorption heat pump |
CN2708220Y (en) | 2004-06-24 | 2005-07-06 | 上海交通大学 | Highly-effective tray low-pressure evaporator for refrigerating plant |
TWI320094B (en) | 2006-12-21 | 2010-02-01 | Spray type heat exchang device | |
US9677818B2 (en) | 2013-07-11 | 2017-06-13 | Daikin Applied Americas Inc. | Heat exchanger |
CN104819604A (en) | 2015-04-27 | 2015-08-05 | 上海理工大学 | Layered flooded evaporator |
CN205807912U (en) | 2016-06-14 | 2016-12-14 | 青岛海尔智能技术研发有限公司 | Multilamellar flooded evaporator and refrigeration, air conditioning system |
-
2018
- 2018-08-13 US US16/766,203 patent/US20200370802A1/en not_active Abandoned
- 2018-08-13 WO PCT/EP2018/071947 patent/WO2019105607A1/en unknown
- 2018-08-13 EP EP18750236.4A patent/EP3717843B1/en active Active
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11619428B2 (en) * | 2018-04-06 | 2023-04-04 | Carrier Corporation | Integrated separator and distributor |
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WO2019105607A1 (en) | 2019-06-06 |
EP3717843A1 (en) | 2020-10-07 |
EP3717843B1 (en) | 2021-09-08 |
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