DE102007021420A1 - Heat exchanger, evaporative refrigeration system and process treatment plant for workpieces - Google Patents

Abstract

A heat exchanger with a first circuit for a Nutzmedium and with a second circuit for a heat exchange medium is described. The circuits are in heat-conducting connection with each other. The second circuit is designed as a separate, closed system. The first circuit can be disassembled independently of the second circuit (FIG. 2B).

Description

The The invention relates to heat exchangers having a first circuit for a working medium and with a second circuit for a heat exchange medium, the circuits with each other in thermally conductive connection.

The The invention further relates to an evaporative refrigeration system with a heat exchanger through which a useful medium flows.

The The invention finally relates to a process engineering Processing plant for workpieces, in which a liquid working fluid from a treatment tank withdrawn, cooled by means of a refrigeration system and then fed back to the treatment tank becomes.

Heat exchanger, Evaporation refrigeration systems and process engineering treatment plants of the aforementioned type are in a variety of forms known.

heat exchangers are components that allow a Nutzmedium by thermally conductive contact with a heat exchange medium to a higher or to bring a lower temperature. For plate heat exchangers this happens over a sandwich-like structure of alternating arranged side by side, mostly plate-shaped cavities or chambers for the working medium and the heat exchange medium. The cavities are by well heat-conducting walls separated from each other.

If the heat exchanger for cooling the Nutzmediums should be used, then the heat exchange medium a liquid, e.g. B. be water, which is lower Temperature is. The colder heat exchange medium absorbs part of the heat of the user medium, changes but not its state of aggregation. In sufficient quantity available heat exchange medium (eg river water) the cooling system can be open. In other cases is the cooling medium after leaving the heat exchanger means a radiator, such as an air or water radiator, cooled and the heat exchanger in a closed Circulation fed again.

alternative The heat exchange medium can also be a special coolant be, by the heat absorption in the heat exchanger evaporates, so changes its state of aggregation, what a greater heat dissipation allows. The vaporized heat exchange medium is then compressed in a compressor and fed to a condenser. An open one System is not possible in this case. An evaporative refrigeration system can with better efficiency, especially with less use of primary energy.

One special application of cooling heat exchangers In the context of interest here is industrial painting of workpieces, in particular the painting of automobile bodies in electric diving systems. Further applications are treatment plants, in which workpieces are treated with warm liquids be, for example, cleaning systems, galvanic systems etc.

In Electric dipping systems are z. B. automobile bodies or others Parts transported through a plunge pool. This is an electric current passed through the plunge pool and the bodies, so that the Paint firmly adheres to the bodywork. The flowing through the dipping bath Electric current heats the paint therein and However, the circulation pump considerably, so you forced is to cool the dipping bath continuously. this happens conventionally with a water cooling of the top first described type in which an easy to clean plate heat exchanger is used, in which the warm paint the Nutzmedium and cold Water is the heat exchange medium.

Electrodeposition baths must be operated continuously, so 365 days in the Year around the clock because the paint would sediment in the plunge pool, if you use the plunge pool for a longer period of time off. On the other hand, from time to time it is necessary to clean the heat exchanger. This maintenance must therefore go very fast, not to the cooling effect to interrupt.

If one now to increase the efficiency or to sink of energy consumption instead of a water-cooled heat exchanger, in particular plate heat exchanger, one with a Would use evaporative cooling, then would be the time required for such maintenance considerably larger. It would have to be the first in terms of its environmental impact is usually problematic Heat exchange medium, in particular a refrigerant, separately emptied and stored and after cleaning the Heat exchanger filled again and the plant be started up.

From the DE 100 35 776 C1 a plate heat exchanger is known in which the walls, by which individual cavities are separated from each other, are peripherally connected to each other by means of elastic seals.

The invention has the object of developing a heat exchanger, an evaporative refrigeration system and a coating device of the type mentioned in that the aforementioned disadvantages are avoided. In particular, it should be possible to disassemble a heat exchanger, in particular for an evaporative refrigeration system, in such a short time so far that a quick maintenance is possible, so that use in continuously operated facilities is possible.

at a heat exchanger of the type mentioned is this Problem solved according to the invention, that the second circuit is formed as a separate, closed system and is operable and that the first cycle independent is removable from the second circuit.

at an evaporation refrigeration system of the type mentioned the object is achieved according to the invention, that the heat exchanger in the aforementioned type is trained.

at a painting device of the type mentioned is the task solved according to the invention that the Refrigeration system as evaporative refrigeration system in the above-mentioned type is formed.

The The object underlying the invention is complete in this way solved.

The Invention makes it possible, the heat exchanger, especially for maintenance and repair tasks, such to disassemble that second circuit with the critical heat exchange medium completely closed and in an ent speaking Mode can continue while the elements of the first Circulation accessible. This is eliminated the need to heat exchange medium first to empty and supply and refill later. In this way, evaporation refrigeration systems are easier operate. Furthermore, an application of evaporative refrigeration systems possible with continuous painting equipment and increased their thermal efficiency.

A preferred embodiment of an inventive Heat exchanger is characterized by being a plate heat exchanger with a plurality of substantially parallel to each other and in the Spaced walls is formed, the walls alternately side by side in heat-conducting Compound arranged first cavities and form second cavities, that of a useful medium or of a heat exchange medium be flowed through, that walls at the edge by means of elastic seals are joined together, and that the first cavities delimiting walls by means of elastic seals and releasably connected are.

These Measures have the advantage of having a proven Type of heat exchanger with large heat exchange surface, as already in the preferred field of application of the invention is used, can be modified according to the invention.

Prefers is there when the second cavities are closed Elements are formed.

These Measure has the advantage that the pocket-like training the cavities in a special way a continuous Operation of the heat exchange medium circuit allowed when the Nutzmedium cycle is dismantled.

there is particularly preferred when in the disassembled state, the first Cavities open and accessible and the second Cavities are closed and pressure-resistant. Especially the second cavities are pressure-resistant up to 30 bar.

These Measure has the advantage that when disassembling the Heat exchanger circuit, in particular a cooling circuit, can continue while the first cavities z. B. be cleaned. A compressive strength of 20 bar corresponds doing the usual system pressure values in cooling circuits of interest here, in which z. B. the specialist known cooling medium R 410 A is used.

Further it is preferred if the walls of the second cavities are directly connected.

at Embodiments of the invention are the second cavities at spaced apart positions of its edge with terminals provided for lines.

These Measure has the advantage that the heat exchange medium the second cavities over their entire volume flows through and therefore a particularly good heat transfer is achieved.

at In a particularly preferred embodiment, the lines as flexible pressure lines for the heat exchange medium educated.

These Measure has the advantage that the elements of the second Cavities during maintenance work within certain limits can be moved without hindering their function and without the second cavities are opened would.

Further, according to the present invention, a good effect is obtained when the first cavities are communicated through passages through the second cavities connected to one another, wherein preferably the passages in the flow direction of the Nutzmediums are arranged alternately at spaced-apart positions in the second cavities.

These Measure has the advantage that a meandering Flow of the user medium arises, which ensures a good heat transfer allows the heat exchange medium.

One preferred embodiment of an inventive Evaporative refrigeration system is characterized by the fact that the heat exchanger with a first, input-side connection for a liquid coolant to a Condenser for a heat exchange medium and with a second, output side port for a gaseous coolant to a condenser feeding compressor can be connected.

alternative or additionally, the heat exchanger can also with a first, input-side connection and with a second, output side connection to one or more further Heat exchanger for a heat exchange medium connectable be, with the other heat exchanger for heating another useful medium is used.

These Measure has the advantage that the overall efficiency improves is because the accumulating waste heat in another station exploited and not released to the atmosphere.

A particularly good effect is achieved when funds provided are to the heat exchanger optionally to the condenser or to connect to the other heat exchanger.

These Measure has the advantage that whenever the waste heat can be recycled, this happens, but also without This further waste heat can be used when working there is no customer for the waste heat.

Prefers is there when the further heat exchanger is a bath, in particular a degreasing, or a dryer or a supply air system heated.

at a preferred embodiment of the treatment plant this is designed as a painting device with a dip tank, in which a paint removed from the dip tank, by means of a refrigeration system cooled and then fed back to the plunge pool becomes.

Further Advantages will be apparent from the description and the attached Drawing.

It it is understood that the above and the following yet to be explained features not only in each case specified combination, but also in other combinations or can be used in isolation, without the scope of the present To leave invention.

embodiments The invention are illustrated in the drawings and in the explained in more detail below description. It demonstrate:

1 : a highly schematic block diagram of a dip coating device;

2A FIG. 2 is a schematic cross-sectional view of an exemplary embodiment of a plate heat exchanger according to the invention, as used in an evaporator of the dip-coating device in FIG 1 can be used, in assembled condition;

2 B : the plate heat exchanger of 2 but disassembled; and

3 a block diagram, similar 1 but for a further embodiment of the invention.

In 1 designated 10 as a whole, a dip painting, as used for example in the automotive industry for painting bodies. The dip painting facility 10 has an electric dip tank 12 on top of that, a varnish bath 14 contains. In the paint bath 14 The bodies are immersed at one end, as with an arrow 16 hinted, and leave the paint bath 14 at the opposite end again, as with an arrow 18 indicated.

In the electro-dip process, the paint bath 14 through the paint bath 14 heated to the body flowing electric current, so it is necessary to cool the paint bath. For this purpose is at a first connection 20 the electric sink 12 Paint removed, cooled and connected to a second port 22 fed back to the paint bath. The paint as the medium to be cooled is hereinafter referred to as "working medium", because the invention is of course not limited to the embodiment described here, but also other media, in the simplest case, water, can be treated.

The useful medium first passes to a first connection for cooling 24 , the input working medium, an evaporator 26 whose essential element is a plate heat exchanger 27 forms the value below based on the 2A and 2 B will be explained in more detail. It leaves the evaporator again via a second connection 28 . the output working medium. From there it becomes the second port 22 the electric sink 12 supplied, so that a closed circuit of the user medium is formed. To maintain the circulation is a pump 30 as a circulation pump, for example, between the first port 20 the electric sink 12 and the first connection 24 arranged the evaporator.

The evaporator 26 also has a third port 32 , the inlet heat exchange medium, on which a liquid at this point heat exchange medium (cooling medium) from a condenser 34 under high pressure via an expansion valve 35 is delivered. The condenser 34 is in turn by means of cooling air 36 cooled. That from a fourth connection 40 of the evaporator 26 , the output heat exchange medium, exiting, gaseous heat exchange medium (cooling medium) is in a compressor 38 compressed and to the liquefier 36 recycled. This also creates a closed circuit with regard to the heat exchange medium.

When Coolant can, for example, the coolant R 410 A can be used in systems with a system pressure of 20 bar is used.

The in 1 shown plant, the operation of the electric sink 12 even apart, essentially only energy via the drive of the compressor 38 fed. The condenser 34 accumulating waste heat is via the cooling air 36 delivered to the atmosphere.

2A shows the details of the plate heat exchanger 27 ,

The plate heat exchanger 27 has a sandwich-like structure. In 2A you can see a first head plate on the left 50 and on the right a second headstock 52 that the plate heat exchanger 27 border laterally and preferably form its supporting mechanical elements. The in each case inwardly facing walls of the head plates 50 and 52 are with 51 and 53 designated.

In the first headstock 50 is a first neck up 54 built in by the first headstock 50 passes through and the first connection 24 of the evaporator 26 forms. Similarly, the second headstock 52 with a second neck 56 provided the second connection 28 of the evaporator 26 represents. In the illustrated embodiment, the nozzles are aligned 54 and 56 together. It goes without saying in this connection that the statements "right", "left", "top", "bottom", etc. are only to be understood as examples and that other configurations are also possible, as known from plate heat exchangers.

To the first headstock 50 closes on the right a first seal 60 on, which is preferably designed as an annular seal. The first seal 60 Adjacent to the right of a first heat exchange plate 62 so that is between the first headstock 50 and the first heat exchange plate 62 a first cavity 61 located. The first heat exchanger plate 62 is a bag-like, self-contained element. It is hollow and thus forms a second cavity 63 , Correspondingly, it is located within a second seal 64 and to the right of the first heat exchanger plate 62 a third cavity 65 , the right of a second heat exchanger plate 66 with a fourth cavity 67 is limited. It then close to the right in the same way a third seal 68 , a fifth cavity 69 , a third heat exchanger plate 70 with a sixth cavity 71 , a fourth seal 72 and a seventh cavity 73 to the right of the inner wall 53 the second headstock 52 is limited. The cavities 61 . 63 . 65 . 67 . 69 . 71 and 73 are preferably flat-cuboid, so rectangular in cross-section, but can also be designed flat cylindrical or flat elliptical.

The heat exchanger plates 62 . 66 , and 70 are each with a thin, good heat conducting wall 74 built up. The first heat exchanger plate 62 is down with a first pass 75 , the second heat exchanger plate 66 above with a second passage 76 and the third heat exchanger plate 70 turn down with a third pass 78 provided, the passages 75 . 76 and 78 the right and left to the heat exchanger plates 62 . 66 and 70 adjacent cavities 61 / 65 . 65 / 69 respectively. 69 / 73 connect with each other.

In this way, the working medium flows through the plate heat exchanger 27 from the first port 24 along a meandering path through the cavities 61 . 65 . 69 and 73 to the second port 28 as with arrows 80 located. The working fluid flows in this way on the walls 74 the heat exchanger plates 62 . 66 and 70 past.

As a result of the heat transfer through the walls 74 through it evaporates through the heat exchanger plates 62 . 66 and 70 flowing through the heat exchanger medium and withdraws the Nutzmedium heat. The Nutzmedium therefore emerges from the second port 28 with significantly lower temperature. That of the condenser 34 supplied heat exchange medium enters the cavities 63 . 67 and 71 the heat exchanger plates 62 . 66 and 70 over the third connection 32 one. It vaporizes on the heat exchanger surfaces, as mentioned, and exits the plate heat exchanger 27 through the fourth connection 40 again, is in the liquefier 34 liquefied again and by means of the compressor 38 again the third connection 32 supplied (see. 1 ).

The sandwich-type arrangement of the plate heat exchanger 27 is characterized on the one hand by the fact that its elements, namely the top plates 50 and 52 , the seals 60 . 64 . 68 and 72 and the heat exchanger plates 62 . 66 and 70 are detachably connected to each other so that it is possible to use the plate heat exchanger 27 to disassemble, as in 2 B shown. By "disassembly" is to be understood in particular that the aforementioned elements are in any case moved so far apart that the perfused by the working medium cavities 61 . 65 . 69 and 73 are accessible for maintenance or cleaning purposes.

On the other hand, the heat exchanger plates 62 . 66 and 70 designed as self-contained, pocket-like and pressure-resistant elements. The heat exchanger plates 62 . 66 and 70 are at their upper ends each with upper ports 86 to the cavities 63 . 67 respectively. 71 provided by flexible pressure pipes 88 to a first manifold 90 are connected, the fourth connection 40 forms. Correspondingly, the heat exchanger plates 62 . 66 and 70 at their lower ends respectively with lower connections 92 provided by flexible pressure pipes 94 to a second manifold 96 connected to the third port 32 forms. The flexibility of the pressure lines 88 and 94 allows the heat exchanger plates 62 . 66 and 70 during disassembly of the plate heat exchanger 27 relative to the seals 60 . 64 . 68 and 72 as well as the head plates 50 and 52 to move as far as necessary for the purposes of cleaning and maintenance mentioned above. The circulation of the heat exchanger medium remains completely closed. This cooling circuit can therefore during maintenance in a corresponding standby mode at full system pressure of z. B. 20 bar continue to operate.

The connecting means required for joining said elements are in the 2A and 2 B for the sake of clarity not shown. It is also understood that it is not absolutely necessary for the purposes mentioned to completely separate all elements (top plates, seals heat exchanger plates) from each other, as in 2 B is shown. For accessibility of the hollow medium through which the working medium flows 61 . 65 . 69 and 73 Rather, it is sufficient if the seals remain connected on one side with the local element, so for example, the first seal 60 with the first headstock 50 if only the connection between the first seal 60 and the first heat exchanger plate 62 is solved. Likewise, you could get the second seal 64 and the third seal 68 firmly with the second heat exchanger plate 66 leave connected and only their connection to the left to the first heat exchanger plate 62 and to the right to the third heat exchanger plate 70 solve for access to the third cavity 65 and to the fifth cavity 69 to create and the like.

In the embodiment of 3 is provided on the evaporator 26 waste heat to be used optionally in another station or several other stations, rather than in the condenser 34 over the cooling air 36 to the atmosphere.

In that regard, is in 3 With 98 hinted that the condenser 34 preferably in a separate room, preferably in the outdoor area, so that the waste heat does not affect the process in the plunge pool 12 loaded.

Between the fourth connection 40 of the evaporator 26 and the inlet of the condenser 34 is in the embodiment of 3 a 3-way valve 100 arranged. The 3-way valve 100 allows the fourth port 40 of the evaporator 26 optionally with a cable 102 to connect in the above too 1 described manner to the inlet of the condenser 34 leads, or with a lead 104 connected to an input of a capacitor side 106 another heat exchanger 108 or several other heat exchanger (not shown) is connected. The output of the heat exchanger 108 is in turn over a line 110 to a collection point 112 connected, located in the entrance of the compressor 38 where is also the outlet of the condenser 34 connected.

The heat exchanger 108 also has a hot side 114 on. This is the output side via a line 116 to another, useful heat consuming station 118 connected. The station 118 In the example shown, a spray pretreatment device in which a heated spray liquid, for example cleaning water, is sprayed onto workpieces and the spray liquid dripping from the workpieces in a liquid tank 122 is collected. The collected spray liquid is then transferred via a pipe 124 and a circulating pump (not shown) back to the warm side 114 fed.

The further heat exchanger 108 can that be in the liquid basin 122 heating bath located, for example, a degreasing, or a dryer or a supply air system.

In this way, the waste heat of the condenser 34 exploited and the efficiency of Improved system through improved utilization of the primary energy used. For periods in which the station 118 is not in operation, can by pressing the 3-way valve back to the condenser 34 be resorted to.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10035776 C1 [0012]

Claims (20)

Heat exchanger having a first circuit for a Nutzmedium and with a second circuit for a heat exchange medium, wherein the circuits are in thermally conductive connection with each other, characterized in that the second circuit is formed and operated as a separate, closed system and that the first circuit regardless of the second circuit is removable. Heat exchanger according to claim 1, characterized in that it is designed as a plate heat exchanger having a plurality of substantially mutually parallel and spaced apart walls (FIG. 74 ) is formed, wherein the walls ( 74 ) alternately arranged side by side in heat-conducting connection first cavities ( 61 . 65 . 69 . 73 ) and second cavities ( 63 . 67 . 71 ), which are flowed through by a useful medium or by a heat exchange medium, that walls ( 74 ) at the edge by means of elastic seals ( 60 . 64 . 68 . 72 ), and that the first cavities ( 61 . 65 . 69 . 73 ) bounding walls ( 51 . 53 . 74 ) by means of elastic seals ( 60 . 64 . 68 . 72 ) and releasably connected to each other. Heat exchanger according to claim 2, characterized in that the second cavities ( 63 . 67 . 71 ) are formed as closed elements. Heat exchanger according to claim 3, characterized in that in the disassembled state, the first cavities ( 61 . 65 . 69 . 73 ) open and accessible and the second cavities ( 63 . 67 . 71 ) are closed and pressure resistant. Heat exchanger according to claim 4, characterized in that the second cavities ( 63 . 67 . 71 ) are pressure-resistant up to 30 bar. Heat exchanger according to one or more of claims 3 to 5, characterized in that the walls ( 74 ) of the second cavities ( 63 . 67 . 71 ) are directly connected. Heat exchanger according to one or more of claims 3 to 6, characterized in that the second cavities ( 63 . 67 . 71 ) at spaced-apart positions of its edge with terminals ( 86 . 92 ) are provided for lines. Heat exchanger according to claim 7, characterized in that the lines as flexible pressure lines ( 88 . 94 ) are formed for the heat exchange medium. Heat exchanger according to one or more of claims 2 to 8, characterized in that the first cavities ( 61 . 65 . 69 . 73 ) via passages ( 75 . 76 . 78 ) through the second cavities ( 63 . 67 . 71 ) are interconnected. Heat exchanger according to claim 9, characterized in that the passages ( 75 . 76 . 78 ) in the flow direction ( 80 ) of the Nutzmediums alternately at spaced-apart positions in the second cavities ( 63 . 67 . 71 ) are arranged. Heat exchanger according to one or more of claims 2 to 10, characterized in that the second cavities ( 63 . 67 . 71 ) Part of an evaporator ( 26 ) or a condenser. Evaporative refrigeration plant with a heat exchanger through which a useful medium flows ( 27 ), characterized in that the heat exchanger ( 27 ) is designed according to one or more of claims 1 to 11. Cooling system, in particular according to claim 12, characterized in that the heat exchanger ( 27 ) with a first, input-side connection ( 32 ) for a liquid coolant to a condenser ( 36 ) for a heat exchange medium and with a second, output-side connection ( 40 ) for a gaseous coolant to a condenser ( 36 ) feeding compressors ( 38 ) is connectable. Refrigeration system according to claim 12 or 13, characterized in that the heat exchanger ( 27 ) with a first, input-side connection ( 32 ) and with a second, output-side connection ( 40 ) to one or more further heat exchangers ( 108 ) is connectable to a heat exchange medium, wherein the further heat exchanger ( 108 ) is used to heat another useful medium. Refrigeration system according to claim 12 and 13, characterized in that means ( 100 . 102 . 104 ) are provided to the heat exchanger ( 27 ) optionally to the condenser ( 34 ) or to the further heat exchanger ( 108 ). Refrigeration system according to claim 15, characterized in that the further heat exchanger ( 108 ) a bath ( 122 ), in particular a degreasing bath, or a dryer or a supply air system heated. Process engineering treatment plant for workpieces, in which a liquid working fluid withdrawn from a treatment vessel, cooled by a refrigeration system and then fed back to the treatment vessel, characterized in that the refrigeration system as an evaporative refrigeration system ( 26 to 40 ) is formed according to one or more of claims 10 to 12. Plant according to claim 17, characterized in that it is used as a painting device with a dip tank ( 12 ) is formed, in which a paint ( 14 ) from the plunge pool ( 12 ), cooled by a refrigeration system and then back to the dip tank ( 12 ) is supplied. Installation according to claim 17 or 18, characterized in that means ( 100 . 102 . 104 ) are provided to the refrigeration system optionally to a condenser ( 34 ) or to a heat exchanger ( 108 ). Plant according to claim 19, characterized in that the heat exchanger ( 108 ) a bath ( 122 ), in particular a degreasing bath, or a dryer or a supply air system heated.