Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K7/00—Constructional details common to different types of electric apparatus
  • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
  • H05K7/2089—Modifications to facilitate cooling, ventilating, or heating for power electronics, e.g. for inverters for controlling motor
  • H05K7/20927—Liquid coolant without phase change
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/04—Heating; Cooling; Heat insulation
  • F04C29/047—Cooling of electronic devices installed inside the pump housing, e.g. inverters
• • 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
  • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
  • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
  • F28D15/0266—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
  • F28F13/06—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media
  • F28F13/08—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by affecting the pattern of flow of the heat-exchange media by varying the cross-section of the flow channels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
  • F28F3/12—Elements constructed in the shape of a hollow panel, e.g. with channels
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F7/00—Elements not covered by group F28F1/00, F28F3/00 or F28F5/00
  • F28F7/02—Blocks traversed by passages for heat-exchange media
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
  • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
  • F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2240/00—Components
  • F04C2240/80—Other components
  • F04C2240/808—Electronic circuits (e.g. inverters) installed inside the machine

Definitions

• the present invention concerns a cooling plate particularly suitable for coupling with a frequency converter.
• the invention also concerns a compressor fed by a frequency converter and equipped with the above mentioned plate for cooling the converter itself.
• a frequency converter is an electronic device that makes it possible to control the number of revolutions of an electric motor
• a converter is often used, for example, for feeding the motors of motor pumps or compressors, whose performance can thus be adapted to the user's needs.
• a frequency converter develops a certain quantity of heat during its operation and that, therefore, it must be properly cooled in order to avoid malfunctions and any possible damage to its electronic components.
• the above mentioned cooling effect is obtained by means of a heat dissipation element placed in contact with the hottest electronic components of the converter, from which it takes the heat in order to transfer it to a cooling fluid with which the heat dissipation element comes into contact.
• the heat dissipation element is often cooled by the same fluid that flows in the cooling system and in the compressor itself.
• the above mentioned heat dissipation element is a coil pipe with uniform diameter, in which said cooling fluid circulates and which is arranged in contact with the hot components of the converter.
• a dissipation plate is added, interposed between the coil and the converter in order to increase the heat exchange surface between the two elements.
• the cooling fluid circulating in the cooling system is used also to cool the heat dissipation element.
• the cooling fluid is drawn downstream of the condenser in the liquid state and is conveyed to the coil of the heat dissipation element, along which it evaporates removing heat from the converter.
• the known coil described above has limited heat exchange efficiency, and makes it necessary to take from the cooling system a correspondingly high cooling fluid flow rate.
• the overall dimensions of the converter and of the relevant heat dissipation element generates a further drawback represented by the fact that it makes it difficult to install a converter in a pre-existing system that is not equipped with such a device.
• the object of the present invention is to overcome all the above mentioned drawbacks that are typical of the known art.
• it is a first object of the invention to carry out a cooling plate for a frequency converter whose efficiency is higher than that of the known heat dissipation elements suited for analogous purposes.
• the increased efficiency of the plate that is the subject of the invention makes it possible to use a lower cooling fluid flow rate compared to the heat dissipation elements of known type capable of removing the same heat flow, which improves the overall efficiency of the system.
• the lower fluid flow rate required makes it possible to reduce the size of the plate of the invention compared to other heat dissipation elements of known type having the same heat dissipation capacity. Therefore, to advantage, the cooling plate that is the subject of the invention is sufficiently compact to be integrated in the compressor together with the converter, so as to further reduce the overall dimensions of the assembly.
• the above mentioned integration makes it possible to reduce the complexity of the system in which the compressor is inserted.
• the compact size offers a further advantage, represented by the fact that the compressor of the invention can be used in existing systems and replace a compressor without converter, with no need to make major changes to the system.
• FIG. 1 shows an axonometric, partial section view of the compressor that is the subject of the invention
• FIG. 2 shows an axonometric view of the cooling plate that is the subject of the invention
• FIG. 3 shows an axonometric view of a detail of the cooling plate that is the subject of the invention
• - Figure 4 is a partial view of a cross section of the cooling plate of Figure 2 along plane IV-IV;
• - Figure 5 is a side view of a cross section of the cooling plate of Figure 2 along plane V-V;
• FIG. 6 shows a plan view of the cooling plate shown in Figure 2;
• FIG. 7 shows an axonometric view of a construction variant of the cooling plate that is the subject of the invention.
• the compressor that is the subject of the invention is shown in Figure 1 , where it is indicated as a whole by 1.
• the compressor 1 comprises a case 2 containing an electric motor 3 fed by a frequency converter 4.
• the electric motor 3 is operatively connected to compression means 5 which preferably but not necessarily comprise a pair of counter-rotating screws.
• the screws define a plurality of chambers 5a, each one provided with an inlet way and a delivery way, in order to contain an operating fluid to be compressed.
• the screws are structured in such a way that, during their rotation, the volume of the chambers 5a decreases, thus compressing the operating fluid.
• the above mentioned screw compressor 1 is known per se and widespread, especially in the field of refrigeration.
• compressor 1 like, for example, positive displacement compressors, reciprocating compressors, vane superchargers, centrifugal compressors, or any other type of compressor, provided that it is equipped with a motor fed by a frequency converter 4.
• the compressor 1 comprises a cooling plate 6 provided with a coupling surface 6a in contact with the frequency converter 4, preferably at the level of the most delicate electronic components that develop the greatest quantity of heat.
• the plate 6 comprises a duct assembly 10 for a cooling fluid which preferably but not necessarily is the same operating fluid that circulates in the compressor 1 .
• the above mentioned fluid has a low temperature and, furthermore, its evaporation can be exploited to obtain the efficient cooling of the plate 6.
• the above mentioned duct assembly 10 is developed between an inlet opening 7 and an outlet opening 8, which define an outflow direction V of the cooling fluid along the duct assembly 10.
• outflow direction V can take different directions along the duct assembly 10, following the more or less curvilinear trajectory defined by the duct assembly 10 itself.
• the surface area of the cross section of the duct assembly 10 increases along the outflow direction V.
• the surface area of the cross section of the duct assembly 10 preferably increases by discrete values along the outflow direction V. More precisely, and as shown in greater detail in Figures from 3 to 6, the duct assembly 10 comprises a plurality of rectilinear ducts 11 arranged side by side and preferably parallel, each one of which has uniform cross section.
• the above mentioned rectilinear ducts 11 can be carried out in a very simple manner, for example by drilling a monobloc body 17, as will be described below.
• the surface area of the cross section of the duct assembly 10 may increase continuously, and not discretely, along the outflow direction V.
• the rectilinear ducts 11 are preferably divided in three groups 12, 13, 14, arranged in series according to the outflow direction V, each one of said groups having an overall flow cross section larger than that of the preceding group.
• a first group 12 and a second group 13 are provided with the same number of ducts 11 , and a first end 12a of each duct of the first group 12 is connected to a first end 13a of a corresponding duct of the second group 13 by means of a corresponding first connection duct 15, one of which is entirely visible in Figure 3.
• the number of groups of ducts can be higher than three. It is also evident that in further construction variants of the invention one or more groups of ducts can have the same overall flow cross section, provided that there are at least two groups of ducts whose overall flow cross sections are different and increasing along the outflow direction V. Regarding the ducts of the third group 14, each one of them has a first end 14a connected, through a second connection duct 16, to a second end 13b of the ducts of the second group 13 opposite the corresponding first end 13a.
• the increasing cross section makes it possible to optimize the speed of the cooling fluid in the various areas of the duct assembly 10 according to the state and specific volume of the fluid itself, taking in consideration the progressive evaporation of the fluid along the duct assembly 10.
• the cross section of the duct assembly 10 can be defined in such a way as to force the fluid to flow at a fixed uniform or variable speed, in order to obtain in any case the maximum heat removal efficiency in each group of ducts 12, 13, 14. Therefore, the duct assembly 10 with increasing cross section gives the cooling plate 6 higher heat exchange efficiency compared to the heat dissipation elements of known type, thus achieving the object of the invention. Consequently, to advantage, the plate 6 of the invention requires a lower cooling fluid flow rate compared to the known heat dissipation elements, with the same heat flow to be dissipated.
• the lower fluid flow rate advantageously makes it possible to proportionally reduce the average flow cross section of the duct assembly 10 and therefore the overall dimensions of the plate 6. Furthermore, the duct assembly 10 is shaped similarly to a coil and therefore the cooling fluid inverts its motion in each one of the successive groups of ducts 12, 13, 14.
• the presence of more than one duct 11 in parallel in some sections of the duct assembly 10 advantageously ensures better distribution of the fluid in the plate 6, in such a way as to further improve its efficiency.
• the ducts of the cooling plate 6 can be provided in any number and arranged in various ways, according to the cooling needs of the frequency converter 4, provided that the duct assembly 10 they make up has an increasing overall cross section.
• the second group of ducts 13 should be preferably included between the first group of ducts 12 and the frequency converter 4, so that the second group of ducts 13 is nearer the coupling surface 6a of the converter 4, where the plate 6 is hotter, and the first group of ducts 12 is farther, where the plate 6 is colder.
• the above mentioned arrangement which can be observed in Figures 2 and 5, advantageously makes it possible to exploit at best the cooling power of the fluid, consequently further increasing the efficiency of the plate 6.
• the cooling fluid has more cooling power when it is in the first group of ducts 12 than when it flows in the second group of ducts 13, where it is already warm.
• the average difference between the temperature of the plate 6 and that of the fluid along the duct assembly 10 is minimal.
• thermodynamics we have a condition that is analogous to that of a countercurrent heat exchange between two fluids that, as is known from thermodynamics, allows the maximum heat exchange efficiency to be obtained with the same fluid flow rate.
• each duct of the duct assembly 10 is a blind hole obtained in a monobloc body 17 belonging to the cooling plate 6.
• each duct of the first group 12 is a first blind hole 18 having the opening 18a arranged on a first side 17a of the monobloc body 17.
• the ducts of the second group 13 and of the third group 14 comprise, respectively, the same number of second blind holes 19 and third blind holes 20 with the corresponding openings 19a, 20a arranged on a second side 17b of the monobloc body 17 opposite said first side 17a.
• connection ducts 15, 16 are respectively fourth blind holes 21.
• the second blind holes 19 preferably have larger overall cross section than the first blind holes 18, as can be observed in the cross section shown in Figure 4.
• the fourth blind holes 21 corresponding to the first connection ducts 15 are preferably orthogonal to the first blind holes 18 and intersect them at the level of the corresponding bottoms 18b.
• the second connection duct 16 it corresponds to a fourth blind hole 21 , preferably orthogonal to the second blind holes 19 and passing at the level of the corresponding bottoms 19b.
• Each one of the openings 19a, 21a of the second blind holes 19 and of the fourth blind holes 21 is closed by a corresponding plug 22, in such a way as to create the duct assembly 10.
• the duct assembly 10 obtained by means of the blind holes
• the plate 6 with the duct assembly 10 integrated therein is structurally simpler than a plate provided with a separate duct assembly.
• the cooling plate 6 also comprises a first head 23 and a second head 24, respectively associated with the first side 17a and the second side 17b of the monobloc body 17.
• first head 23 there is an inlet manifold, not represented herein, operatively connected to the inlet opening 7 of the plate 6 and communicating with the openings of each first blind hole 18.
• the first head 23 preferably comprises also the inlet opening 7.
• the second head 24 it is provided with an outlet manifold 25, visible in particular in Figures 2 and 6, which places the third blind holes 20 in communication with each other at the level of the corresponding openings 20a and which preferably but not necessarily is also a blind hole whose end 25a is closed by a corresponding plug 22.
• FIG. 7 shows a construction variant of the cooling plate that is the subject of the invention, indicated as a whole by 30.
• This variant differs from the previous one due to the fact that the blind holes 33 of the third group of ducts 31 are operatively connected to one another by means of ducts 34 which are external to the plate 30 and to which the outlet opening 32 belongs. Consequently, the plate 30 is not provided with the second head, meaning that its construction is less difficult.
• the compressor 1 is more compact than the compressors with frequency converter of known type, thus achieving another object of the invention.
• the plate 6, 30 is arranged in the compressor 1 , it is particularly advantageous to cool it by means of the same operating fluid that circulates in the compressor 1.
• the outlet opening 8, 32 of the plate 6, 30 communicates with the variable volume chamber 5a, so that the fluid flowing out of the plate 6, 30 flows back in the main circuit of the system directly at the level of the variable volume chamber 5a.
• the plate 6, 30, being integrated in the case 2 of the compressor 1 can be connected to the chamber 5a through a connection way 2a housed in the case 2 of the compressor 1 , advantageously avoiding an external pipe that would mean increasing the overall dimensions.
• the cooling fluid is tapped at the liquid state and under high pressure from the main circuit in which the compressor 1 is inserted.
• the above mentioned condition takes place, as is known and as previously mentioned, downstream of the condenser.
• the high pressure makes it possible to convey the tapped fluid through a throttling valve 9 and successively through the duct assembly 10 of the plate 6, which advantageously makes it possible to avoid using an apposite pumping device.
• the throttling valve 9, operatively connected to the inlet opening 7 of the cooling plate 6, lowers the pressure and the temperature of the tapped fluid.
• the fluid flows along the duct assembly 10 of the cooling plate 6, where it absorbs the heat produced by the frequency converter 4 and at the same time evaporates.
• Said throttling valve 9 is preferably but not necessarily associated with the first head 23, between the inlet opening 7 and the inlet manifold.
• the plate and the compressor that are the subjects of the invention achieve all the set objects.
• the invention achieves the object to produce a cooling plate that is more efficient than the heat dissipation elements of the known type, thus making it possible to limit the overall dimensions of the plate itself.
• the invention achieves the object to produce a compressor with frequency converter that is more compact than the analogous compressors of known type.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Compressor (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Details Of Measuring And Other Instruments (AREA)

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• 2008
  • 2008-05-09 IT ITVI20080106 patent/ITVI20080106A1/it unknown
• 2009
  • 2009-05-08 EP EP09742450A patent/EP2286646A1/de active Pending
  • 2009-05-08 CN CN200980116492.8A patent/CN102017827B/zh active Active
  • 2009-05-08 WO PCT/IB2009/005535 patent/WO2009136277A1/en active Application Filing

Non-Patent Citations (1)

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